2022 Volume 59 Issue 3 Pages 293-299
Exercise increases sympathetic nerve activity and arterial pressure simultaneously; this increase is sustained in proportion to exercise intensity. It is caused by an acute rightward and upward shift of the arterial baroreceptor reflex. In this study, we observed the acute rightward and upward shift of the baroreflex curve for renal sympathetic nerve activity during exercise in rats. Similar shifts in the baroreflex curve for sympathetic nerve activity may occur in the entire body, resulting in a uniform increase in sympathetic activity throughout the body during exercise. The increase in sympathetic nerve activity proportional to exercise intensity is likely caused by the afferent neuronal activity originating from the contracting muscle to the central nervous system; this afferent information results in activity proportional to the degree of muscle contraction. Although central command can change sympathetic nerve activity in an organ-specific manner, it acts to increase sympathetic nerve activity uniformly throughout the body during exercise. In this way, an acute shift in the arterial baroreceptor reflex causes a simultaneous and sustained increase in sympathetic nerve activity and arterial pressure during exercise.
