THE RELATIONSHIP OF VARIOUS ANESTHETIC AGENTS TO THE ACTION OF PITUITRIN, PITRESSIN AND PITOCIN

Abstract

Posterior pituitary prepns. may produce undesirable respiratory or circulatory side-effects. Since incompatibility may exist between pituitary prepns. and some of the anesthetic agents, an evaluation of the pharmacologic and therapeutic uses of these prepns. was attempted in 84 expts. on 26 dogs. Prepns. used were pituitrin (1U./kg. diluted in 5 ml. and injected intraven. within 50 sec.), pitressin (2 U./kg.), pitocin (1 U./kg.), and pituitrin-epinephrine. A dilute acetic acid soln. was used as a control. Anesthetics used were cyclopropane, ether, chloroform, nembutal, chlore-tone, and procaine. Ecg. and direct blood pressure recordings were made. The following phenomena were observed after the admn. of pituitrin or pitressin during anesthesia (1) marked hypotension that could be corrected by epinephrine, (2) peripheral and coronary circulatory insufficiency, (3) cardiac irregularities in light anesthesia (also in unanesthetized animals) but less frequently in deep anesthesia. Pitocin produced no marked deleterious effects. Since pituitary prepns. exhibit species variation, implications of these expts. may not apply to man. The working concept formulated was that pituitrin causes coronary constriction with resultant myocardial hypoxia.