Adaptation of the human carotid baroreceptor‐cardiac reflex.

Abstract

Four intensities of neck suction were applied for 5 s in healthy young men to determine the time course of decay of carotid baroreflex sinus node inhibition. Peak responses occurred at about 1.25 s after the onset of baroreceptor stimulation and were proportional to the intensity of stimulation. Responses declined steadily during the remaining period of stimulation. The rate of decay of sinus node inhibition was described well by a power function and was proportional to the intensity of baroreceptor stimulation. .beta.-Adrenergic blockade did not alter the rate of decay of baroreflex sinus node inhibition. Adaptation of the integrated baroreceptor-cardiac reflex occurs in man and apparently follows the same time course as adaptation of individual baroreceptor units in experimental animals.