Subject(s)
Amphetamine/administration & dosage , Animals , Blood Pressure/drug effects , Cats , Depression, Chemical , Dogs , Female , Male , Mephentermine/pharmacologySubject(s)
Acetylcholine/antagonists & inhibitors , Animals , Anura , Dogs , Drug Interactions , Ethanolamines/pharmacology , Isoxsuprine/pharmacology , Mephentermine/pharmacology , Muscle Contraction/drug effects , Neuromuscular Junction/drug effects , Phenoxybenzamine/pharmacology , Physostigmine/antagonists & inhibitors , Rats , Tubocurarine/pharmacologyABSTRACT
Vasopressor effects of epinephrine, norepinephrine, ephedrine, phenylephrine, methoxamine and of mephentermine were compared in resrpinized dogs with or without nitrous oxide-oxygen-halothane anesthesia. The results are as follows: (1) Epinephrine and norepinephrine were shown to have the most potent pressor effect in reserpinized and nitrous oxide-oxygen-halothane-anesthetized dogs. Phenylephrine, methoxamine, mephen-termine and ephedrine were less potent in decreasing order. (2) Decrease in mean arterial pressure was less marked in dogs reserpinized and anesthetized with nitrous oxide-oxygen-halothane than in reserpinized but unanesthetized dogs. (3) It revealed that nitrous oxide-oxygen-halothane anesthesia potentiated the vasopressor effects of the sympathomimetic amines studied. Nitrous oxide-oxygen-halothane anesthesia is implicated to exert an sympathomimetic effect.