Effects of renal denervation on renin release in sodium depleted dogs

To examine the role of the renal nerves in the increased plasma renin activity (PRA) of sodium depletion, two protocols were used. In protocol I (five dogs), PRA increased significantly with sodium depletion both before and after bilateral renal denervation and the responses did not differ (P < .05). In protocol 2 (five dogs), PRA increased (P < .005) with sodium depletion and remained elevated for 8 days after renal denervation (P < .05); however, PRA declined slightly from the predenervation values for PRA (P < .05). Five other dogs were studied similarly following sham denervation; a similar progressive decline in PRA occurred after sham denervation (P < .05). Direct measurement of renin secretion in four sodium depleted, renal denervated dogs and in five normal dogs demonstrated higher values in the sodium depleted animals (P < .005). Intrarenal arterial infusion of papaverine had no effect on renin secretion in normal dogs, but decreased renin secretion in sodium depleted dogs (P < .05). It is concluded that the increased renin secretion during sodium depletion in not dependent on intact renal nerves, but appears to be dependent on a renal vascular receptor.