title: Alterations in myocardial adenylate cyclase in spontaneously hypertensive rats.
abstract: Particulate fractions of myocardium taken from spontaneously hypertensive rats (SHR) contained an adenylate cyclase system that was less responsive than normotensive Wistar Kyoto rats to norepinephrine, isoproterenol (mixed beta-agonist), salbutamol (beta 2-agonist), dobutamine (beta 1-agonist), dopamine, histamine, and glucagon. Addition of 5'-guanylylimidodiphosphate to the SHR myocardial preparation again yielded a lessened sensitivity to all agents except norepinephrine, dopamine, and histamine. Chronic treatment of SHR with clonidine and a high dose of propranolol produced a cardiac enzyme that was insensitive to activation by norepinephrine. Similar treatment with a low dose of propranolol did not alter myocardial responses to norepinephrine.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000420:Albuterol / Q000494:pharmacology; D000818:Animals; D002395:Catecholamines / Q000494:pharmacology; D003000:Clonidine / Q000494:pharmacology; D005934:Glucagon / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology; D006973:Hypertension / Q000201:enzymology*; D008297:Male; D009206:Myocardium / Q000201:enzymology* / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology; D051381:Rats
chemical_list: D000318:Adrenergic beta-Agonists; D002395:Catecholamines; D006165:Guanylyl Imidodiphosphate; D006632:Histamine; D005934:Glucagon; D011433:Propranolol; D000262:Adenylyl Cyclases; D003000:Clonidine; D000420:Albuterol