TY - JOUR T1 - MODIFICATION OF THE CHRONOTROPIC ACTION OF SYMPATHOMIMETIC AMINES BY RESERPINE IN THE HEART-LUNG PREPARATION OF THE DOG JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 63 LP - 69 VL - 133 IS - 1 AU - J. Liebman Y1 - 1961/07/01 UR - http://jpet.aspetjournals.org/content/133/1/63.abstract N2 - In the heart-lung preparation (HLP) of normal and reserpine-pretreated dogs, complete dose-response curves for four sympathomimetic amines (tyramine, amphetamine, phenylpropanolamine and Synephrine) were obtained. The curves were found to have an ascending and a subsequent descending limb. Reserpine pretreatment affected the shape of the dose-response curves in the following ways: 1) there was no change, as with Synephrine; 2) there was a depression of the maximum, as with tyramine and amphetamine; and 3) there was a shift of the curve to the right with some depression of the maximum, as with phenylpropanolamine. These observations are compatible with the concept that sympathomimetic agents can be divided into three groups: 1) those with direct action; 2) those with indirect action; and 3) those with "mixed" (direct and indirect) action. ER -