Alterations in beta-adrenergic stimulation of myocardial adenylate cyclase in endotoxic rats.
The effect of in vivo endotoxin administration on adenylate cyclase in rat ventricular membranes was studied. Basal, fluoride-, and 5'-guanylylimidodiphosphate-stimulated adenylate cyclase activities were not affected throughout the period of endotoxicosis. Isoproterenol-stimulated adenylate cyclase activity was not different at 0.5 or 3 h after endotoxin. At the agonal stage, the isoproterenol dose-response curve was shifted significantly to the right in myocardial membranes from endotoxic rats, but there was no significant decrease in maximum stimulated activity. These data indicate that endotoxicosis does not inhibit the adenylate cyclase enzyme system but does decrease stimulation of adenylate cyclase via beta-adrenergic receptors when the animal is approaching death.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004731:Endotoxins / Q000494:pharmacology*; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009206:Myocardium / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D012475:Salmonella; D012969:Sodium Fluoride / Q000494:pharmacology; D013268:Stimulation, Chemical
D004731:Endotoxins; D011943:Receptors, Adrenergic, beta; D006165:Guanylyl Imidodiphosphate; D012969:Sodium Fluoride; D000262:Adenylyl Cyclases; D007545:Isoproterenol