Apyrase
Bedbugs
Adenosine Triphosphate
Receptors, Purinergic P2
Adenosine Diphosphate
Receptors, Purinergic P2Y2
Receptors, Purinergic P2Y1
Solanum tuberosum
Platelet Aggregation
Plant Tubers
Receptors, Purinergic P2X1
Receptors, Purinergic P2X7
Purinergic P2 Receptor Antagonists
5'-Nucleotidase
Salivary Glands
Suramin
Receptors, Purinergic P2X
Oxamniquine
Phlebotomus
Purinergic P2X Receptor Antagonists
Metabolic acidosis-induced retinopathy in the neonatal rat. (1/540)
PURPOSE: Carbon dioxide (CO2)-induced retinopathy (CDIR) in the neonatal rat, analogous to human retinopathy of prematurity (ROP), was previously described by our group. In this model, it is possible that CO2-associated acidosis provides a biochemical mechanism for CDIR. Therefore, the effect of pure metabolic acidosis on the developing retinal vasculature of the neonatal rat was investigated. METHODS: A preliminary study of arterial blood pH was performed to confirm acidosis in our model. In neonatal rats with preplaced left carotid artery catheters, acute blood gas samples were taken 1 to 24 hours after gavage with either NH4Cl 1 millimole/100 g body weight or saline. In the subsequent formal retinopathy study, 150 newborn Sprague-Dawley rats were raised in litters of 25 and randomly assigned to be gavaged twice daily with either NH4Cl 1 millimole/100 g body weight (n = 75) or saline (n = 75) from day 2 to day 7. After 5 days of recovery, rats were killed, and retinal vasculature was assessed using fluorescein perfusion and ADPase staining techniques. RESULTS: In the preliminary pH study, the minimum pH after NH4Cl gavage was 7.10+/-0.10 at 3 hours (versus 7.37+/-0.03 in controls, mean +/- SD, P < 0.01). In the formal retinopathy study, preretinal neovascularization occurred in 36% of acidotic rats versus 5% of controls (P < 0.001). Acidotic rats showed growth retardation (final weight 16.5+/-3.0 g versus 20.2+/-2.6 g, P < 0.001). The ratio of vascularized to total retinal area was smaller in acidotic rats (94%+/-4% versus 96%+/-2%, P < 0.001). CONCLUSIONS: Metabolic acidosis alone induces neovascularization similar to ROP in the neonatal rat. This suggests a possible biochemical mechanism by which high levels of CO2 induce neovascularization and supports the suggestion that acidosis may be an independent risk factor for ROP. (+info)Specific inhibition of ADP-induced platelet aggregation by clopidogrel in vitro. (2/540)
1. The thienopyridine clopidogrel is a specific inhibitor of ADP-induced platelet aggregation ex vivo. No direct effects of clopidogrel (< or = 100 microM) on platelet aggregation in vitro have been described so far. 2. Possible in vitro antiaggregatory effects (turbidimetry) of clopidogrel were studied in human platelet-rich plasma and in washed platelets. 3. Incubation of platelet-rich plasma with clopidogrel (< or = 100 microM) for up to 8 h did not result in any inhibition of ADP (6 microM)-induced platelet aggregation. 4. Incubation of washed platelets with clopidogrel resulted in a time- (maximum effects after 30 min) and concentration-dependent (IC50 1.9+/-0.3 microM) inhibition of ADP (6 microM)-induced platelet aggregation. Clopidogrel (30 microM) did not inhibit collagen (2.5 microg ml(-1))-, U46619 (1 microM)- or thrombin (0.1 u ml(-1))-induced platelet aggregation. The inhibition of ADP-induced aggregation by clopidogrel (30 microM) was insurmountable indicating a non-equilibrium antagonism of ADP actions. The R enantiomer SR 25989 C (30 microM) was significantly less active than clopidogrel (30 microM) in inhibiting platelet aggregation (32+/-5% vs 70+/-1% inhibition, P < 0.05, n = 5). 5. In washed platelets, clopidogrel (< or = 30 microM) did not significantly reverse the inhibition of prostaglandin E1 (1 microM)-induced platelet cyclic AMP formation by ADP (6 microM). 6. The antiaggregatory effects of clopidogrel were unchanged when the compound was removed from the platelet suspension. However, platelet inhibition by clopidogrel was completely abolished when albumin (350 mg ml(-1)) was present in the test buffer. 7. It is concluded that clopidogrel specifically inhibits ADP-induced aggregation of washed platelets in vitro without hepatic bioactivation. Inhibition of ADP-induced platelet aggregation by clopidogrel in vitro occurs in the absence of measurable effects on the reversal of PGE1-stimulated cyclic AMP by ADP. (+info)Functional characterization of rat ecto-ATPase and ecto-ATP diphosphohydrolase after heterologous expression in CHO cells. (3/540)
The recently cloned ecto-ATPase and ecto-apyrase (ecto-ATP diphosphohydrolase) are plasma-membrane-bound enzymes responsible for the extracellular degradation of nucleoside 5'-triphosphates and nucleoside 5'-diphosphates. We expressed the rat-derived enzymes in CHO cells to compare their molecular and functional properties. Sequence-specific polyclonal antibodies differentiate between the two proteins and reveal identical molecular masses of 70-80 kDa. Both enzymes are stimulated by either Ca2+ or Mg2+ and reveal a broad substrate specificity towards purine and pyrimidine nucleotides. Whereas ecto-apyrase hydrolyzes nucleoside 5'-diphosphates at a rate approximately 20-30% lower than nucleoside-5'-triphosphates, ecto-ATPase hydrolyzes nucleoside-5'-diphosphates only to a marginal extent. The sensitivity of the two enzymes to the inhibitors of P2 receptors suramin, PPADS and reactive blue differs. Hydrolysis of ATP by ecto-ATPase leads to the accumulation in the medium of extracellular ADP as an intermediate product, whereas ecto-apyrase dephosphorylates ATP directly to AMP. Our results suggest that previous data describing extracellular hydrolysis of ATP by a variety of intact cellular systems with unidentified ecto-nucleotidases may be explained by the coexpression of ecto-ATPase and ecto-apyrase. (+info)A nod factor binding lectin with apyrase activity from legume roots. (4/540)
A lectin isolated from the roots of the legume, Dolichos biflorus, binds to Nod factors produced by rhizobial strains that nodulate this plant and has a deduced amino acid sequence with no significant homology to any lectin reported to date. This lectin also is an enzyme that catalyzes the hydrolysis of phosphoanhydride bonds of nucleoside di- and triphosphates; the enzyme activity is increased in the presence of carbohydrate ligands. This lectin-nucleotide phosphohydrolase (LNP) has a substrate specificity characteristic of the apyrase category of phosphohydrolases, and its sequence contains four motifs characteristic of this category of enzymes. LNP is present on the surface of the root hairs, and treatment of roots with antiserum to LNP inhibits their ability to undergo root hair deformation and to form nodules on exposure to rhizobia. These properties suggest that this protein may play a role in the rhizobium-legume symbiosis and/or in a related carbohydrate recognition event endogenous to the plant. (+info)Inhibition of an ecto-ATP-diphosphohydrolase by azide. (5/540)
Cell surface ATPases (ecto-ATPases or E-ATPases) hydrolyze extracellular ATP and other nucleotides. Regulation of extracellular nucleotide concentration is one of their major proposed functions. Based on enzymatic characterization, the E-ATPases have been divided into two subfamilies, ecto-ATPases and ecto-ATP-diphosphohydrolases (ecto-ATPDases). In the presence of either Mg2+ or Ca2+, ecto-ATPDases, including proteins closely related to CD39, hydrolyze nucleoside diphosphates in addition to nucleoside triphosphates and are inhibited by millimolar concentrations of azide, whereas ecto-ATPases appear to lack these two properties. This report presents the first systematic kinetic study of a purified ecto-ATPDase, the chicken oviduct ecto-ATPDase (Strobel, R.S., Nagy, A.K., Knowles, A.F., Buegel, J. & Rosenberg, M.O. (1996) J. Biol. Chem. 271, 16323-16331), with respect to ATP and ADP, and azide inhibition. Km values for ATP obtained at pH 6.4 and 7.4 are 10-30 times lower than for ADP and the catalytic efficiency is greater with ATP as the substrate. The enzyme also exhibits complicated behavior toward azide. Variable inhibition by azide is observed depending on nucleotide substrate, divalent ion, and pH. Nearly complete inhibition by 5 mm azide is obtained when MgADP is the substrate and when assays are conducted at pH 6-6.4. Azide inhibition diminishes when ATP is the substrate, Ca2+ as the activating ion, and at higher pH. The greater efficacy of azide in inhibiting ADP hydrolysis compared to ATP hydrolysis may be related to the different modes of inhibition with the two nucleotide substrates. While azide decreases both Vmax and Km for ADP, it does not alter the Km for ATP. These results suggest that the apparent affinity of azide for the E.ADP complex is significantly greater than that for the free enzyme or E.ATP. The response of the enzyme to three other inhibitors, fluoride, vanadate, and pyrophosphate, is also dependent on substrate and pH. Taken together, these results are indicative of a discrimination between ADP and ATP by the enzyme. A mechanism of azide inhibition is proposed. (+info)Insertion of atToc34 into the chloroplastic outer membrane is assisted by at least two proteinaceous components in the import system. (6/540)
Toc34 is a member of the outer membrane translocon complex that mediates the initial stage of protein import into chloroplasts. Toc34, like most outer membrane proteins, is synthesized in the cytosol at its mature size without a cleavable transit peptide. The majority of outer membrane proteins do not require thermolysin-sensitive components on the chloroplastic surface or ATP for their insertion into the outer membrane. However, different results have been obtained concerning the factors required for Toc34 insertion into the outer membrane. Using an Arabidopsis homologue of pea Toc34, atToc34, we show that the insertion of atToc34 was greatly reduced by thermolysin pretreatment of chloroplasts as assayed either by protease digestion or by alkaline extraction. The insertion was also dependent on the presence of ATP or GTP. A mutant of atToc34 with the GTP-binding domain deleted still required ATP for optimal insertion, indicating that ATP was used by other protein components in the import system. The ATP-supported insertion was observed even in thermolysin-pretreated chloroplasts, suggesting that the protein component responsible for ATP-stimulated insertion is a different protein from the thermolysin-sensitive component that assists atToc34 insertion. (+info)Platelet-released ADP stabilizes PAF-induced rabbit platelet aggregation by stabilizing intracellular calcium. (7/540)
AIM: To examine whether platelet-released adenosine diphosphate (ADP) would contribute to the stabilization of rabbit platelet aggregation induced by platelet activating factor (PAF). METHODS: Rabbit platelet aggregation induced by PAF was measured turbimetrically. ADP release from rabbit platelets stimulated by PAF was determined by HPLC. Intracellular Ca2+ was measured using Ca(2+)-sensitive fluorescent indicator Fura 2-AM. RESULTS: PAF > or = 1 nmol.L-1 induced full platelet aggregation, which did not deaggregate over 5 min after aggregation reached peak. Platelet aggregation was deaggregated in a concentration-dependent manner by subsequent addition of ADP scavenger ATP-diphosphohydrolase (apyrase) at 5-100 mg.L-1. PAF 3 nmol.L-1 stimulated release of ADP (29% vs 6% of control), and elicited a rapid rise in intracellular calcium ([Ca2+]i) which peaked at approximately 15 s. Then the [Ca2+]i gradually decayed from 585 +/- 80 nmol.L-1 within 100 s to a low level (364 +/- 82 nmol.L-1). Apyrase 100 mg.L-1, added 2 min after PAF, reduced [Ca2+]i to a lower level (171 +/- 29 nmol.L-1). CONCLUSION: Platelet-released ADP stabilizes PAF-induced rabbit platelet aggregation by stabilizing [Ca2+]i at elevated level. (+info)CD39-L4 is a secreted human apyrase, specific for the hydrolysis of nucleoside diphosphates. (8/540)
The human ecto-apyrase gene family consists of five reported members (CD39, CD39-L1, CD39-L2, CD39-L3, and CD39-L4). The family can be subdivided into two groups by conservation of proposed structural domains. The CD39, CD39-L1, and CD39-L3 genes all encode hydrophobic portions in their carboxy and amino termini, serving as transmembrane domains for CD39 and potentially for the other two members. CD39-L2 and CD39-L4 genes encode hydrophobic portions in their amino termini, suggesting that they might encode secreted apyrases. We demonstrate that the CD39-L4 gene encodes the first reported human secreted ecto-apyrase. COS-7 cells transfected with a CD39-L4 expression construct utilizing the naturally occurring leader peptide express recombinant protein outside of the cells. This expression can be blocked by brefeldin A, a chemical that inhibits a step in mammalian secretory pathways. We also demonstrate expression of CD39-L4 message in macrophages, suggesting that the protein is present in the circulation. Furthermore, we show that CD39-L4 is an E-type apyrase, is dependent on calcium and magnesium cations, and has high degree of specificity for NDPs over NTPs as enzymatic substrates. A potential physiological role in hemostasis and platelet aggregation is presented. (+info)Apyrase is an enzyme that catalyzes the hydrolysis of nucleoside triphosphates (like ATP or GTP) to nucleoside diphosphates (like ADP or GDP), releasing inorganic phosphate in the process. It can also hydrolyze nucleoside diphosphates to nucleoside monophosphates, releasing inorganic pyrophosphate.
This enzyme is widely distributed in nature and has been found in various organisms, including bacteria, plants, and animals. In humans, apyrases are present in different tissues, such as the brain, platelets, and red blood cells. They play essential roles in several biological processes, including signal transduction, metabolism regulation, and inflammatory response modulation.
There are two major classes of apyrases: type I (also known as nucleoside diphosphate kinase) and type II (also known as NTPDase). Type II apyrases have higher substrate specificity for nucleoside triphosphates, while type I apyrases can hydrolyze both nucleoside tri- and diphosphates.
In the medical field, apyrases are sometimes used in research to study platelet function or neurotransmission, as they can help regulate purinergic signaling by controlling extracellular levels of ATP and ADP. Additionally, some studies suggest that apyrase activity might be involved in certain pathological conditions, such as atherosclerosis, thrombosis, and neurological disorders.
Bedbugs are small, wingless insects that belong to the family Cimicidae. The scientific name for the most common species of bedbug is Cimex lectularius. Adult bedbugs are oval-shaped, flat, and reddish-brown in color, while nymphs (immature bedbugs) are smaller, lighter in color, and translucent.
Bedbugs feed on the blood of humans and other warm-blooded animals, usually at night when their hosts are asleep. They are attracted to body heat and carbon dioxide exhaled by their hosts. Bedbug bites can cause itchy red welts or bumps on the skin, but they are not known to transmit any diseases.
Bedbugs can be found in a variety of places where people sleep or rest for extended periods, including homes, hotels, hostels, and college dormitories. They can hide in cracks and crevices in furniture, walls, floors, and bedding, making them difficult to detect and eliminate.
To prevent bedbug infestations, it is recommended to inspect second-hand furniture carefully before bringing it into your home, use protective encasements on mattresses and box springs, and avoid storing items under beds or near walls. If you suspect a bedbug infestation, contact a pest management professional for assistance.
Adenosine Triphosphate (ATP) is a high-energy molecule that stores and transports energy within cells. It is the main source of energy for most cellular processes, including muscle contraction, nerve impulse transmission, and protein synthesis. ATP is composed of a base (adenine), a sugar (ribose), and three phosphate groups. The bonds between these phosphate groups contain a significant amount of energy, which can be released when the bond between the second and third phosphate group is broken, resulting in the formation of adenosine diphosphate (ADP) and inorganic phosphate. This process is known as hydrolysis and can be catalyzed by various enzymes to drive a wide range of cellular functions. ATP can also be regenerated from ADP through various metabolic pathways, such as oxidative phosphorylation or substrate-level phosphorylation, allowing for the continuous supply of energy to cells.
Purinergic P2 receptors are a type of cell surface receptor that bind to purine nucleotides and nucleosides, such as ATP (adenosine triphosphate) and ADP (adenosine diphosphate), and mediate various physiological responses. These receptors are divided into two main families: P2X and P2Y.
P2X receptors are ionotropic receptors, meaning they form ion channels that allow the flow of ions across the cell membrane upon activation. There are seven subtypes of P2X receptors (P2X1-7), each with distinct functional and pharmacological properties.
P2Y receptors, on the other hand, are metabotropic receptors, meaning they activate intracellular signaling pathways through G proteins. There are eight subtypes of P2Y receptors (P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, P2Y12, P2Y13, and P2Y14), each with different G protein coupling specificities and downstream signaling pathways.
Purinergic P2 receptors are widely expressed in various tissues, including the nervous system, cardiovascular system, respiratory system, gastrointestinal tract, and immune system. They play important roles in regulating physiological functions such as neurotransmission, vasodilation, platelet aggregation, smooth muscle contraction, and inflammation. Dysregulation of purinergic P2 receptors has been implicated in various pathological conditions, including pain, ischemia, hypertension, atherosclerosis, and cancer.
Adenosine diphosphate (ADP) is a chemical compound that plays a crucial role in energy transfer within cells. It is a nucleotide, which consists of a adenosine molecule (a sugar molecule called ribose attached to a nitrogenous base called adenine) and two phosphate groups.
In the cell, ADP functions as an intermediate in the conversion of energy from one form to another. When a high-energy phosphate bond in ADP is broken, energy is released and ADP is converted to adenosine triphosphate (ATP), which serves as the main energy currency of the cell. Conversely, when ATP donates a phosphate group to another molecule, it is converted back to ADP, releasing energy for the cell to use.
ADP also plays a role in blood clotting and other physiological processes. In the coagulation cascade, ADP released from damaged red blood cells can help activate platelets and initiate the formation of a blood clot.
I am not aware of a widely recognized medical definition for the term "Mimosa." In general, it may refer to a type of plant or a cocktail made with champagne and orange juice. If you are looking for information on a specific medical condition or concept, please provide more context so that I can give you a more accurate and helpful response. Is there something specific you had in mind?
Purinergic P2Y2 receptors are a type of G-protein coupled receptor (GPCR) that bind to and are activated by extracellular nucleotides, such as ATP and UTP. These receptors play a role in various physiological processes, including regulation of inflammation, smooth muscle contraction, and wound healing.
P2Y2 receptors are widely expressed in various tissues, including the respiratory, gastrointestinal, and urinary tracts, as well as the skin and central nervous system. They have been shown to play a role in the pathophysiology of several diseases, such as cystic fibrosis, asthma, and cancer.
Activation of P2Y2 receptors leads to a variety of cellular responses, including increased intracellular calcium levels, activation of protein kinases, and regulation of gene expression. These downstream signaling events can ultimately lead to changes in cell behavior, such as increased proliferation, migration, or secretion of cytokines and other mediators.
In summary, Purinergic P2Y2 receptors are a type of GPCR that bind to extracellular nucleotides and play a role in various physiological processes and diseases. Activation of these receptors leads to downstream signaling events that can ultimately affect cell behavior.
Purinergic P2Y1 receptors are a type of G-protein coupled receptor (GPCR) that bind to purine nucleotides, such as adenosine triphosphate (ATP) and adenosine diphosphate (ADP). These receptors play a role in various physiological processes, including platelet activation, smooth muscle contraction, and neurotransmission.
The P2Y1 receptor, in particular, is activated by ADP and has been shown to be involved in platelet aggregation, vascular smooth muscle contraction, and neuronal excitability. It signals through the Gq/11 family of G proteins, leading to the activation of phospholipase C-β (PLC-β) and the production of inositol trisphosphate (IP3) and diacylglycerol (DAG), which ultimately result in calcium mobilization and protein kinase C (PKC) activation.
In a medical context, P2Y1 receptors have been implicated in various pathological conditions, including thrombosis, hypertension, and neurodegenerative disorders. Therefore, drugs that target these receptors may have therapeutic potential for the treatment of these conditions.
"Solanum tuberosum" is the scientific name for a plant species that is commonly known as the potato. According to medical and botanical definitions, Solanum tuberosum refers to the starchy, edible tubers that grow underground from this plant. Potatoes are native to the Andes region of South America and are now grown worldwide. They are an important food source for many people and are used in a variety of culinary applications.
Potatoes contain several essential nutrients, including carbohydrates, fiber, protein, vitamin C, and some B vitamins. However, they can also be high in calories, especially when prepared with added fats like butter or oil. Additionally, potatoes are often consumed in forms that are less healthy, such as French fries and potato chips, which can contribute to weight gain and other health problems if consumed excessively.
In a medical context, potatoes may also be discussed in relation to food allergies or intolerances. While uncommon, some people may have adverse reactions to potatoes, including skin rashes, digestive symptoms, or difficulty breathing. These reactions are typically caused by an immune response to proteins found in the potato plant, rather than the tubers themselves.
Platelet aggregation is the clumping together of platelets (thrombocytes) in the blood, which is an essential step in the process of hemostasis (the stopping of bleeding) after injury to a blood vessel. When the inner lining of a blood vessel is damaged, exposure of subendothelial collagen and tissue factor triggers platelet activation. Activated platelets change shape, become sticky, and release the contents of their granules, which include ADP (adenosine diphosphate).
ADP then acts as a chemical mediator to attract and bind additional platelets to the site of injury, leading to platelet aggregation. This forms a plug that seals the damaged vessel and prevents further blood loss. Platelet aggregation is also a crucial component in the formation of blood clots (thrombosis) within blood vessels, which can have pathological consequences such as heart attacks and strokes if they obstruct blood flow to vital organs.
A plant tuber is not a medical term per se, but rather a term from botany. However, I can certainly provide a definition for you.
Tubers are specialized underground stems or roots that serve as storage organs for many types of plants. They consist of enlarged structures filled with nutrients, such as carbohydrates, proteins, and other organic compounds. Tubers can be classified into two main categories: true tubers and false tubers.
True tubers are swollen underground stems, such as those found in potatoes (Solanum tuberosum). They have nodes and internodes like aboveground stems, but they lack leaves or buds. Instead, they have small bumps called "eyes" that contain dormant buds, which can sprout to produce new plants when conditions are favorable.
False tubers, on the other hand, are enlarged roots, such as those found in cassava (Manihot esculenta). They do not have nodes and internodes like true tubers but instead store nutrients in their fleshy tissues.
While plant tubers may not have a direct medical definition, they are essential to human health and nutrition. Many tuber crops provide important sources of carbohydrates, vitamins, minerals, and other nutrients in diets around the world.
Purinergic P2X1 receptors are a type of ligand-gated ion channel that is activated by the binding of ATP (adenosine triphosphate), a purine nucleotide. These receptors are permeable to cations such as calcium, sodium, and potassium ions. P2X1 receptors are widely expressed in various tissues, including the cardiovascular system, nervous system, and urinary system. They play a role in several physiological processes, including neurotransmission, smooth muscle contraction, and platelet aggregation.
P2X1 receptors are composed of three subunits that form a homotrimeric complex. Upon activation by ATP, the channel opens, allowing cations to flow through the membrane. This ion flux can trigger various intracellular signaling pathways and modulate cellular functions.
In summary, Purinergic P2X1 receptors are a type of ATP-activated ion channel that play important roles in several physiological processes and are widely expressed in various tissues throughout the body.
Purinergic P2X7 receptors are a type of ligand-gated ion channel that are activated by the binding of extracellular adenosine triphosphate (ATP) to the P2X7 receptor subunit. These receptors play important roles in various physiological and pathophysiological processes, including inflammation, immune response, pain perception, and cell death.
Upon activation of P2X7 receptors, there is an increase in membrane permeability to small cations such as Na+, K+, and Ca2+, which can lead to the depolarization of the cell membrane. Prolonged activation of these receptors can result in the formation of large pores that allow for the passage of larger molecules, including inflammatory mediators and even small proteins. This can ultimately lead to the induction of apoptosis or necrosis in certain cells.
P2X7 receptors are widely expressed in various tissues, including the brain, spinal cord, immune cells, and epithelial cells. In recent years, there has been growing interest in targeting P2X7 receptors for therapeutic purposes, particularly in the context of inflammatory diseases and chronic pain.
Purinergic P2 receptor antagonists are pharmaceutical agents that block the activity of P2 receptors, which are a type of cell surface receptor that binds extracellular nucleotides such as ATP and ADP. These receptors play important roles in various physiological processes, including neurotransmission, inflammation, and platelet aggregation.
P2 receptors are divided into two main subfamilies: P2X and P2Y. The P2X receptors are ligand-gated ion channels that allow the flow of ions across the cell membrane upon activation, while the P2Y receptors are G protein-coupled receptors that activate intracellular signaling pathways.
Purinergic P2 receptor antagonists are used in clinical medicine to treat various conditions, such as chronic pain, urinary incontinence, and cardiovascular diseases. For example, the P2X3 receptor antagonist gefapixant is being investigated for the treatment of refractory chronic cough, while the P2Y12 receptor antagonists clopidogrel and ticagrelor are used to prevent thrombosis in patients with acute coronary syndrome.
Overall, purinergic P2 receptor antagonists offer a promising therapeutic approach for various diseases by targeting specific receptors involved in pathological processes.
5'-Nucleotidase is an enzyme that is found on the outer surface of cell membranes, including those of liver cells and red blood cells. Its primary function is to catalyze the hydrolysis of nucleoside monophosphates, such as adenosine monophosphate (AMP) and guanosine monophosphate (GMP), to their corresponding nucleosides, such as adenosine and guanosine, by removing a phosphate group from the 5' position of the nucleotide.
Abnormal levels of 5'-Nucleotidase in the blood can be indicative of liver or bone disease. For example, elevated levels of this enzyme in the blood may suggest liver damage or injury, such as that caused by hepatitis, cirrhosis, or alcohol abuse. Conversely, low levels of 5'-Nucleotidase may be associated with certain types of anemia, including aplastic anemia and paroxysmal nocturnal hemoglobinuria.
Medical professionals may order a 5'-Nucleotidase test to help diagnose or monitor the progression of these conditions. It is important to note that other factors, such as medication use or muscle damage, can also affect 5'-Nucleotidase levels, so results must be interpreted in conjunction with other clinical findings and diagnostic tests.
Salivary glands are exocrine glands that produce saliva, which is secreted into the oral cavity to keep the mouth and throat moist, aid in digestion by initiating food breakdown, and help maintain dental health. There are three major pairs of salivary glands: the parotid glands located in the cheeks, the submandibular glands found beneath the jaw, and the sublingual glands situated under the tongue. Additionally, there are numerous minor salivary glands distributed throughout the oral cavity lining. These glands release their secretions through a system of ducts into the mouth.
Suramin is a medication that has been used for the treatment of African sleeping sickness, which is caused by trypanosomes. It works as a reverse-specific protein kinase CK inhibitor and also blocks the attachment of the parasite to the host cells. Suramin is not absorbed well from the gastrointestinal tract and is administered intravenously.
It should be noted that Suramin is an experimental treatment for other conditions such as cancer, neurodegenerative diseases, viral infections and autoimmune diseases, but it's still under investigation and has not been approved by FDA for those uses.
Purinergic P2X receptors are a type of ligand-gated ion channel that are activated by the binding of extracellular ATP (adenosine triphosphate) and other purinergic agonists. These receptors play important roles in various physiological processes, including neurotransmission, pain perception, and immune response.
P2X receptors are composed of three subunits that form a functional ion channel. There are seven different subunits (P2X1-7) that can assemble to form homo- or heterotrimeric receptor complexes with distinct functional properties.
Upon activation by ATP, P2X receptors undergo conformational changes that allow for the flow of cations, such as calcium (Ca^2+^), sodium (Na^+^), and potassium (K^+^) ions, across the cell membrane. This ion flux can lead to a variety of downstream signaling events, including the activation of second messenger systems and changes in gene expression.
Purinergic P2X receptors have been implicated in a number of pathological conditions, including chronic pain, inflammation, and neurodegenerative diseases. As such, they are an active area of research for the development of novel therapeutic strategies.
Oxamniquine is an antiparasitic medication used to treat infections caused by certain types of intestinal worms, specifically the parasite called *Strongyloides stercoralis*. It works by inhibiting the motility and reproduction of the parasites, leading to their eventual elimination from the body.
It is important to note that oxamniquine is not commonly used in clinical practice due to the availability of other effective antiparasitic agents and its potential for causing adverse effects such as nausea, vomiting, dizziness, and headache. Additionally, it should only be administered under the supervision of a healthcare professional and according to approved guidelines, as improper use can lead to treatment failure or the development of drug-resistant parasites.
"Phlebotomus" is a genus of sandflies, which are small flies that are known to transmit various diseases such as leishmaniasis. These flies are typically found in warm and humid regions around the world, particularly in the Mediterranean, Middle East, Africa, and Asia. The females of this genus feed on the blood of mammals, including humans, for egg production. It is important to note that not all species of Phlebotomus are vectors of disease, but those that are can cause significant public health concerns in affected areas.
Purinergic P2X receptor antagonists are pharmaceutical agents that block the activation of P2X receptors, which are ligand-gated ion channels found in the cell membranes of various cell types, including excitable cells such as neurons and muscle cells. These receptors are activated by extracellular adenosine triphosphate (ATP) and play important roles in a variety of physiological processes, including neurotransmission, pain perception, and inflammation.
P2X receptor antagonists work by binding to the receptor and preventing ATP from activating it, thereby blocking its downstream effects. These drugs have potential therapeutic uses in various medical conditions, such as chronic pain, urinary incontinence, and ischemia-reperfusion injury. However, their development and use are still in the early stages of research, and more studies are needed to fully understand their mechanisms of action and safety profiles.
Purinergic P2 receptor agonists are substances that bind and activate purinergic P2 receptors, which are a type of cell surface receptor found in many tissues throughout the body. These receptors are activated by extracellular nucleotides, such as ATP (adenosine triphosphate) and ADP (adenosine diphosphate), and play important roles in various physiological processes, including neurotransmission, muscle contraction, and inflammation.
P2 receptors are divided into two main subfamilies: P2X and P2Y. P2X receptors are ligand-gated ion channels that allow the flow of ions across the cell membrane when activated, while P2Y receptors are G protein-coupled receptors that activate intracellular signaling pathways.
Purinergic P2 receptor agonists can be synthetic or naturally occurring compounds that selectively bind to and activate specific subtypes of P2 receptors. They have potential therapeutic applications in various medical conditions, such as pain management, cardiovascular diseases, and neurological disorders. However, their use must be carefully monitored due to the potential for adverse effects, including desensitization of receptors and activation of unwanted signaling pathways.
Apyrase
ENTPD1
Ectonucleoside triphosphate diphosphohydrolase 4
Sequencing
ENTPD3
ENTPD5
ENTPD6
Ornithodoros savignyi
Adenosine diphosphate
Marta Bunster
Pyrosequencing
A. K. Mukherjee
Adenosine diphosphatase
Hirudo medicinalis
Ixodes holocyclus
Massive parallel sequencing
Mosquito bite allergy
List of MeSH codes (D08)
List of EC numbers (EC 3)
Apyrase - Wikipedia
Functional analyses of two arabidopsis apyrases
The potato-specific apyrase is apoplastically localized and has influence on gene expression, growth, and development :: MPG...
PDB 1S18 | Chain STRUCTURE AND PROTEIN DESIGN OF HUMAN APYRASE | 1S18 A | 3D Structure | canSARS
Thrombin-induced platelet endostatin release is blocked by a proteinase activated receptor-4 (PAR4) antagonist
Modulating inflammatory monocytes with a unique microRNA gene signature ameliorates murine ALS
Expression of Medicago truncatula ecto-apyrase MtAPY1;1 in leaves of Nicotiana benthamiana restricts necrotic lesions induced...
Human CD39/ENTPD1 Alexa Fluor® 488-conjugated Antibody FAB4397G-100UG: R&D Systems
BV510 Mouse Anti-Human CD39
What is Pyrosequencing?
Purified anti-human CD39 Maxpar Ready Antibody anti-CD39 - A1
Real-time in vivo imaging of extracellular ATP in the brain with a hybrid-type fluorescent sensor | eLife
Role of the Domestic Chicken (Gallus gallus)in the Epidemiology of Urban Visceral Leishmaniasis in Brazil - Volume 8, Number 12...
Phenolphthalein bisphosphate 95 68807-90-9
Eric Davies | Plant and Microbial Biology
Publikationen von Karin Köhl | Max-Planck-Institut für Molekulare Pflanzenphysiologie
Publications of Mark Stitt | Max Planck Institute of Molecular Plant Physiology
Pyrosequencing - wikidoc
Kinesin-8-specific loop-2 controls the dual activities of the motor domain according to tubulin protofilament shape | Nature...
Regulation of T Helper 17 by Bacteria: An Approach for the Treatment of Hepatocellular Carcinoma
Terry L. Kirley, PhD
Non-catalytic motor domains enable processive movement and functional diversification of the kinesin-14 Kar3 | eLife
Search | Preprints.org
CANT1 Antibody | CSB-PA13099A0Rb | Cusabio
SNP-based real-time pyrosequencing as a sensitive and specific tool for identification and differentiation of Rickettsia...
Amotosalen/UVA pathogen inactivation technology reduces platelet activability, induces apoptosis and accelerates clearance ...
acylsphingosine deacylase
Тренинговая Тетрадь По Математике (Задачи На Доли) 2007
Bibliografia 2015 - Pagina 132 - Endometriosi.it
Adenosine5
- Apyrase (EC 3.6.1.5, ATP-diphosphatase, adenosine diphosphatase, ADPase, ATP diphosphohydrolase) is a calcium-activated plasma membrane-bound enzyme (magnesium can also activate it) (EC 3.6.1.5) that catalyses the hydrolysis of ATP to yield AMP and inorganic phosphate. (wikipedia.org)
- The salivary apyrases of blood-feeding arthropods are nucleotide hydrolysing enzymes that are implicated in the inhibition of host platelet aggregation through the hydrolysis of extracellular adenosine diphosphate. (wikipedia.org)
- An adenosine diphosphate (ADP) scavenger, apyrase, inhibited the platelet aggregation induced by thrombin, but not the release of endostatin. (nih.gov)
- The DNA fragments are incubated with DNA polymerase, ATP sulfurylase, and apyrase enzymes, and adenosine 5' phosphosulfate and luciferin substrates. (news-medical.net)
- ssDNA template is hybridized to a sequencing primer and incubated with the enzymes DNA polymerase , ATP sulfurylase , luciferase and apyrase , and with the substrates adenosine 5´ phosphosulfate (APS) and luciferin . (wikidoc.org)
Platelet2
- We reasoned that the presence of prostacyclin (PGI 2 ) during the washing procedure to inhibit platelet activation and of apyrase in the suspending milieu to degrade trace amounts of ADP released from platelets and thus prevent the desensitization of the ADP receptors, might mimic the inhibitory role of the vascular endothelium, known to express ectonucleotidase activities and to produce PGI 2 , the natural strong vasodilator and inhibitor of platelet activation. (haematologica.org)
- Apyrases (which remove platelet agonist ADP) phosphatases (which degrade procoagulant polyphosphates) and sphingomyelinase had been bought at lower transcriptional amounts. (academicediting.org)
Subcellular localization2
- The investigation of the subcellular localization of apyrases showed that some fraction of apyrase was localized on cell periphery. (utexas.edu)
- To place these results in context, we determined the subcellular localization of the potato-specific apyrase. (mpg.de)
Unused nucleotides and ATP1
- Unused nucleotides and ATP degrade to apyrase, allowing the reaction to start again with another nucleotide. (news-medical.net)
Metabolism1
- however, there were no direct effects of apyrase inhibition on tuber metabolism. (mpg.de)
Enzyme3
- In the treatment arm, an ATP hydrolyzing enzyme, apyrase, was applied directly to the site immediately after injury. (usuhs.edu)
- An inward current (Ix) was identified and this current was blocked by the P2 receptor antagonist, suramin, and inhibited by the ATP-degrading enzyme, apyrase. (ucl.ac.uk)
- Grupo de enzimas que catalizan la hidrólisis de enlaces difosfato en compuestos tales como nucleósidos difosfatos y trifosfatos, y anhídridos que contienen grupos sulfonilo, como el adenililsulfato (Enzyme Nomenclature, 1992). (bvsalud.org)
Nucleotide2
- Unincorporated nucleotides and ATP are degraded by the apyrase, and the reaction can restart with another nucleotide. (wikidoc.org)
- ATP-Diphophohydrolases, Apyrases, and Nucleotide Phosphohydrolases: Biochemical Properties and Functions (A.R. Beaudoin, J. Sevigny, and M. Picher). (elsevier.com)
Germination1
- The double knockout (DKO) apyrase pollen displayed a complete block of pollen germination, which implicated this step as the cause of the lethality of apyrase double knockout mutants. (utexas.edu)
Expression3
- Because of the lethality of apy1apy2 double mutants, RNA interference (RNAi) was performed as an alternative approach to posttranscriptionally silence the expression of apyrases. (utexas.edu)
- Previously, promoter-GUS fusions showed that high expression of apyrase was associated with areas of rapid growth and regions with high auxin levels. (utexas.edu)
- DNA microarrays revealed that decreased expression of apyrase leads to increased levels of transcripts coding for cell wall proteins involved in growth and genes involved in energy transfer and starch synthesis. (mpg.de)
Activity3
- Pollen tube elongation was inhibited by suppression of apyrase activity using anti-apyrase antibodies or by chemical inhibitors of apyrases. (utexas.edu)
- Silencing of the apyrase gene family with RNA interference constructs under the control of the constitutive 35S promoter led to a strong decrease in apyrase activity to below 10% of the wild-type level. (mpg.de)
- It has also been used as a component of modified Tryptose phosphate/phenolphthalein/methyl green (M-TPMG) agar to detect enteroinvasive Escherichia coli (EIEC) apyrase activity. (sigmaaldrich.com)
Animals1
- They favor the hypothesis that Arabidopsis apyrases, like their homologs in animals, control the levels of ATP in the extracelluar space, and this control allows them to act as key regulators in growth. (utexas.edu)
Role3
- In this dissertation, I describe the important role of two Arabidopsis apyrases in the regulation of plant growth. (utexas.edu)
- In this study, we used reverse genetic and biochemical approaches to investigate the role of potato (Solanum tuberosum)-specific apyrase. (mpg.de)
- We describe the evidence that underlies both this fact and that potato-specific apyrase has a crucial role in regulating growth and development. (mpg.de)
Growth1
- The suppression of apyrases in the RNAi lines resulted in a dwarf phenotype in overall vegetative growth and dramatically reduced growth in primary root and etiolated hypocotyls. (utexas.edu)
Enzymes1
- Apyrases are enzymes that catalyze the hydrolysis of nucleotide diphosphates and triphosphates in a calcium or magnesium-dependent manner. (nih.gov)
Human apyrase2
- APT Therapeutics has applied proprietary protein engineering strategies to develop APT102, an innovative human apyrase therapy for the treatment of thrombotic diseases. (pipelinereview.com)
- By combining their strengths with our own research and development expertise in human apyrase therapy, we have a great opportunity to develop a breakthrough drug that will safely and substantially improve the lives of millions of patients worldwide. (pipelinereview.com)
Nucleotides1
- The encoded protein is an endo-apyrase and may play a role in salvaging nucleotides from lysosomes. (nih.gov)
EATP1
- Ecto-apyrases help controlling eATP content in the ECM and thus contribute to mediating the plant growth and defense response to environmental stress. (chinbullbotany.com)
Protein3
- From NCBI Gene: The protein encoded by this gene is similar to E-type nucleotidases (NTPases)/ecto-ATPase/apyrases. (nih.gov)
- This gene encodes a member of the apyrase protein family. (nih.gov)
- Recombinant apyrase rPorSP15, yellow-related protein rPorSP24, ParSP25-like protein rPorSP65, D7-related protein rPorSP67, and antigen 5-related protein rPorSP76 were tested using ELISA with sera of domestic animals from L. donovani foci in Ethiopia where Ph. (meganhardenfitness.com)
Agents1
- The toxicology of some putative medicinal agents acting on this cascade (such as apyrase) is satisextend-betweeny ( Marcus et al. (ika.ie)