title: Cyclic 3',5'-adenosine monophosphate phosphodiesterase (cAMP PDE) and cyclic 3',5'-guanosine monophosphate phosphodiesterase (cGMP PDE) in microvessels isolated from bovine cortex.
abstract: It was established that microvessels of a bovine cortex exhibit significant cyclic 3',5'-adenosine monophosphate phosphodiesterase (cAMP PDE) and cyclic 3',5'-guanosine monophosphate phosphodiesterase (cGMP PDE) activities. These activities are dependent on the presence of Mg2+. Absence of Ca2+ was virtually without effect. When both Mg2+ and Ca2+ were absent, PDE activities increased compared with activities observed in the absence of Mg2+. Xanthines (caffeine, theobromine, and theophylline) were better inhibitors of cAMP PDE than of cGMP PDE. Imidazole, in very high concentration (1 X 10(-2) M) only, exhibited PDE stimulatory activity at high concentrations of both substrates. Otherwise, it exhibited PDE-inhibitory properties.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism*; D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism*; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D002540:Cerebral Cortex / Q000098:blood supply / Q000201:enzymology*; D000242:Cyclic AMP; D006152:Cyclic GMP; D007093:Imidazoles / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology; D008833:Microcirculation; D013805:Theobromine / Q000494:pharmacology; D013806:Theophylline / Q000494:pharmacology
chemical_list: D007093:Imidazoles; D002110:Caffeine; D013806:Theophylline; D000242:Cyclic AMP; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D006152:Cyclic GMP; D008274:Magnesium; D013805:Theobromine; D002118:Calcium