Cardiac Pharmacology of Anesthetics - 1. Preliminary Observation of Halothane's Inhibitory Action on Cardiac Metabolism

마취제(痲醉劑)의 심장약리학적(心臟藥理學的) 연구(硏究) 제1보(第1報) 전신마취제(全身痲醉劑) Halothane의 심장대사(心臟代謝) 억제작용(抑制作用)에 관(關)한 기초적(基礎的) 고찰(考察)

Certain metabolic aspects of halothane's cardiac depressant action on the contractility of the myocardium were elucidated from a sudy of the effect of pyruvate on halothane-depressed rat atria. Approximately 6 mg% halothane was required to maintain a 50% depression of the contractility of rat atria suspended in a modified Krebs-Ringer bicarbonate glucose medium, pH 7.4, $30^{\circ}C$ for a 2 hr. period. Pyruvate was found to restore partially the contractility of halothane-depressed atria. The maximally effective concentration of pyruvate was 2.5 mM. There was minimal pyruvate effect on the force of contraction of control atria. The effect of pyruvate on halothane-depressed atria was shown to be due to the pyruvate and not the sodium ion of the sodium pyruvate. Pyruvate was found to produce no increase in the contractility of atria depressed by hypertonic medium, but caused a further depression. Selected aspects regarding the action of halothane on glucose metabolism in myocardial cells are discussed. The results are consistent with the hypothesis that at least a part of the negative inotropic action of halothane is due to an inhibition of glucose uptake or utilization in the glycolytic pathway.