The effects of sympathomimetic drugs on renal vessels.

The effects of sympathomimetic drugs on renal blood flow in anesthetized dogs were investigated by insertion of a rotameter in the renal artery. The drugscan be grouped into four types: Type A: Sympathomimetic drugs that are capable of constricting renal vessels when injected into the renal artery and intravenously: levarterenol, epinephrine, phenylephrine, metaraminol, methoxamine and naphazoline. Type B: Drugs that are capable of constricting renal vessels when injected into the renal artery; when these drugs are injected intravenously, renal vasoconstriction is not always encountered: ephedrine, phenylpropanolamine, hydroxyamphetamine and compound 45-50. Type C: Drugs that have no important renal actions when injected into the renal artery; when these drugs are injected intravenously, renal blood flow is increased as a result of their systemic pressor effect: methamphetamine, pseudoephedrine, amphetamine, pholedrine, methylaminoheptane, tuaminoheptane, mephentermine and phenylpropylmethylamine. Type D: Drugs that have a local renal dilator action when injected into the renal artery; when injected intravenously, renal blood flow is decreased as a result of their arterial depressor effect: isoproterenol, nylidrin, isoprophenamine, methoxyphenamine and cyclopentamine.