Stimulatory and inhibitory reflexes from somatic receptors: effect on renin release

The effect of stimulation of skeletal muscle somatic receptor afferents on renal function and renin release was examined in anesthetized dogs (bilateral carotid occlusion and vagotomy) with controlled renal arterial pressure. Afferent sciatic nerve stimulation (20-40 V, 1 ms) at 0.6-1.5 Hz elicited cardiovascular pressor responses, renal vasoconstriction, and stimulation of renin release, whereas at 0.3-0.8 Hz cardiovascular depressor responses and inhibition of renin release without changes in renal blood flow were found. Renal denervation abolished the inhibition of renin release but not the cardiovascular depressor response to afferent sciatic nerve stimulation at 20-40 V, 1 ms, and 0.3-0.8 Hz. Peripheral somatic afferent nerves contain fibers which, when appropriately stimulated, produce either pressor or depressor cardiovascular responses. At constant renal arterial pressure, increases in renin release occur with pressor responses, whereas decreases in renin release, mediated by the renal nerves, occur with depressor responses.