title: [Inhibition of the cyclic AMP splitting myocardial nucleotide gydrolase by 5-methyl-7-diethylamino-s-triazol-(1,5-alpha)pyrimidine (rocornal)].
abstract: 5-Methyl-7-diethylamino-s-triazolo-(1,5-alpha)pyrimidine (Rocornal, trapidil), which has been introduced in clinical medicine as a coronary vasodilatator, competitively inhibits the cyclic AMP splitting nucleotidehydrolase (phosphodiesterase) from the heart muscle. The K1 value for Rocornal is 0.14 +/- 0.016 mM. The enzyme inhibition by this compound is abolished after an exchange of the diethylamino-group in C-7 position against dimethylamine and chloride. The proved triazolo-pyrimidines were without effect on myocardial adenylate cyclase activity. It is concluded that the vasodilatory effect of Rocornal may be realized in smooth muscle cells by an inhibition of cyclic AMP breakdown.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002417:Cattle; D000242:Cyclic AMP / Q000378:metabolism; D004791:Enzyme Inhibitors; D009206:Myocardium / Q000201:enzymology; D010727:Phosphoric Diester Hydrolases; D011743:Pyrimidines / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D011743:Pyrimidines; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases; D000262:Adenylyl Cyclases
vernacular_title: Hemmung der zyklo-AMP spaltenden Nukleotidhydrolase des Herzens durch 5-Methyl-7-diäthylamino-s-triazol-(1,5-alpha)pyrimidin (Rocornal)