Method for Studying Competence of the Body's Blood Pressure Regulatory Mechanisms and Effect of Pressoreceptor Denervation

Abstract

A method for alternate flow of blood into and out of the circulatory system under controlled conditions is described. [DELTA]P/[DELTA]V was found to be approx. 3 times as great in pressoreceptor dener-vated animals as in normals. It was also found that during rapid cycles of inflow and outflow pressoreceptors reflexes do not have time to moderate the pressure changes. On the other hand, when the cycles of inflow and outflow had a duration of more than 2 min., the shift of fluid from the tissues to the circulation and in the opposite direction appeared to aid greatly the moderator effect of the pressoreceptors. Sudden inflow or outflow of blood caused a train of oscillatory cycles in the blood pressures of normal dogs, but this did not occur in pressoreceptor denervated dogs nor in spinally anesthetized dogs. Because of the similar periods of these oscillatory cycles and those of Traube-Hering waves, it is postulated that Traube-Hering waves might be due to presso-receptor-sympathetic oscillation.