These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Cardiotonic agents. 7. Inhibition of separated forms of cyclic nucleotide phosphodiesterase from guinea pig cardiac muscle by 4,5-dihydro-6-[4-(1H-imidazol-1-yl)phenyl]-3(2H)-pyridazinones and related compounds. Structure-activity relationships and correlation with in vivo positive inotropic activity.
    Author: Sircar I, Weishaar RE, Kobylarz D, Moos WH, Bristol JA.
    Journal: J Med Chem; 1987 Nov; 30(11):1955-62. PubMed ID: 2822926.
    Abstract:
    The structure-activity relationships of a series of 4,5-dihydro-6-[4-(1H-imidazol-1-yl)phenyl]-3(2H)-pyridazinones and related compounds were investigated for the in vivo inhibition of different forms of cyclic nucleotide phosphodiesterase (PDE) isolated from guinea pig ventricular muscle. With few exceptions, these 4,5-dihydropyridazinones were potent inhibitors of cardiac type III phosphodiesterase, which is a low Km, cyclic AMP specific form of the enzyme. The inhibitory effects on cardiac type I and type II phosphodiesterase, both of which hydrolyze cyclic AMP as well as cyclic GMP, were minimal. The most selective PDE III inhibitor was CI-930 (10), the 5-methyl analogue of imazodan (CI-914, 1), with an IC50 of 0.6 microM. The most potent inhibitor of PDE III was the 4,5,6,7-tetrahydrobenzimidazole analogue of 10 (31), with an IC50 of 0.15 microM. This paper describes the structural features that impart both selectivity for inhibiting type III phosphodiesterase and potency of inhibition. In addition, correlations between in vitro PDE inhibitory potency, in vivo positive inotropic potency, and physicochemical properties are discussed.
    [Abstract] [Full Text] [Related] [New Search]