Effect of low-level renal nerve stimulation on renin release from nonfiltering kidneys

The mechanism whereby renal nerves influence the renin-release response to aortic constriction was examined in a nonfiltering ureter-occluded kidney preparation in anesthetized dogs. The kidney was rendered nonfiltering by a combination of mannitol infusion and ureteral occlusion. Suprarenal aortic constriction reduced renal perfusion pressure to 61 +/- 7 mmHg and increased renin release from 16.7 +/- 4.1 to 26.1 +/- 6.0 U/min. At normal renal perfusion pressure, low-frequency renal nerve stimulation (0.25 Hz) increased renin release by 11.6 +/- 4.2 to 25.1 +/- 7.6 U/min. The effect of combined low-level renal nerve stimulation and aortic constriction on renin release was additive; renin release increased by 24.6 +/- 6.5 to 39.5 +/- 7.3 U/min. Propranolol or metoprolol, administered intrarenally at 2 microgram . min-1 . kg-1, abolished the renin-release response to low-level renal nerve stimulation at normal renal perfusion pressure. These data provide evidence that low-frequency renal nerve stimulation influences the renin-release response to reduction in renal perfusion pressure in a nonfiltering ureter-occluded kidney with an inoperative macula densa receptor mechanism. The neural effect on renin release at normal renal perfusion pressure is mediated via beta 1-adrenoceptors probably located on the juxtaglomerular granular cells.