A phosphodiesterase 4 inhibitor with antidepressant properties.

A cyclic nucleotide phosphodiesterase subfamily that is found predominantly in inflammatory cells and may play a role in the regulation of CELL-MEDIATED IMMUNITY. The enzyme family includes over twenty different variants that occur due to multiple ALTERNATIVE SPLICING of the mRNA of at least four different genes.

Compounds which inhibit or antagonize the biosynthesis or actions of phosphodiesterases.

A group of compounds that are derivatives of oxo-pyrrolidines. A member of this group is 2-oxo pyrrolidine, which is an intermediate in the manufacture of polyvinylpyrrolidone. (From Merck Index, 11th ed)

Enzymes that catalyze the hydrolysis of CYCLIC AMP to form adenosine 5'-phosphate. The enzymes are widely distributed in animal tissue and control the level of intracellular cyclic AMP. Many specific enzymes classified under this heading demonstrate additional spcificity for 3',5'-cyclic IMP and CYCLIC GMP.

A cyclic nucleotide phosphodiesterase subfamily that is inhibited by the binding of CYCLIC GMP to an allosteric domain found on the enzyme and through phosphorylation by regulatory kinases such as PROTEIN KINASE A and PROTEIN KINASE B. The two members of this family are referred to as type 3A, and type 3B, and are each product of a distinct gene. In addition multiple enzyme variants of each subtype can be produced due to multiple alternative mRNA splicing.

'Purines' is a term used in medical biochemistry to refer to naturally occurring heterocyclic aromatic organic compounds, which include adenine and guanine (components of nucleotides and nucleic acids), and are formed in the body from purine bases through various metabolic processes.

An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.

Inhibitor of phosphodiesterases.

A CALCIUM and CALMODULIN-dependent cyclic nucleotide phosphodiesterase subfamily. The three members of this family are referred to as type 1A, type 1B, and type 1C and are each product of a distinct gene. In addition, multiple enzyme variants of each subtype can be produced due to multiple alternative mRNA splicing. Although the type 1 enzymes are classified as 3',5'-cyclic-AMP phosphodiesterases (EC 3.1.4.17), some members of this class have additional specificity for CYCLIC GMP.

A class of enzymes that catalyze the hydrolysis of one of the two ester bonds in a phosphodiester compound. EC 3.1.4.

**Pyridazine** is a heterocyclic organic compound, consisting of a six-membered ring containing two nitrogen atoms, which is a basic structure found in certain pharmaceuticals and natural compounds, though it does not have a specific medical definition itself as a component or condition.

A potent cyclic nucleotide phosphodiesterase inhibitor; due to this action, the compound increases cyclic AMP and cyclic GMP in tissue and thereby activates CYCLIC NUCLEOTIDE-REGULATED PROTEIN KINASES

Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)

A transfer RNA which is specific for carrying arginine to sites on the ribosomes in preparation for protein synthesis.

A class of ciliate protozoa. Characteristics include the presence of a well developed oral apparatus and oral cilia being clearly distinct from somatic cilia.

NATIONAL LIBRARY OF MEDICINE service for health professionals and consumers. It links extensive information from the National Institutes of Health and other reviewed sources of information on specific diseases and conditions.

An MAO inhibitor that is effective in the treatment of major depression, dysthymic disorder, and atypical depression. It also is useful in the treatment of panic disorder and the phobic disorders. (From AMA, Drug Evaluations Annual, 1994, p311)

A genus of zygomycetous fungi in the family Mucoraceae, order MUCORALES, forming mycelia having a metallic sheen. It has been used for research on phototropism.

A condition with congenital and acquired forms causing recurrent ulcers in the fingers and toes. The congenital form exhibits autosomal dominant inheritance; the acquired form is found in workers who handle VINYL CHLORIDE. When acro-osteolysis is accompanied by generalized OSTEOPOROSIS and skull deformations, it is called HAJDU-CHENEY SYNDROME.