Effects of barodenervation on cardiovascular responses to static muscular contraction.

The purpose of this study was to measure blood flow to various tissues during static muscular contraction in anesthetized cats and to evaluate if the baroreflex modulates the cardiovascular responses to muscular contraction. Contraction of the hindlimb muscles induced by ventral root stimulation caused increases in arterial pressure (delta 37.8 +/- 5.5 mmHg) and heart rate (delta 13.9 +/- 3.1 beats/min). Increases in blood flow to the heart, working skeletal muscles, and selected areas of the central nervous system occurred during muscular contraction. Blood flow to visceral organs did not change during muscular contraction. Baroreceptor-denervated cats showed a greater rise in arterial pressure (delta 55.5 +/- 5.5 mmHg) during muscular contraction than did the baroreceptor-intact cats. However, blood flow responses were similar in both groups. Thus the baroreceptor reflex modulates the pressor response without changing the alteration in blood flow during induced muscular contraction in anesthetized cats.