LACK OF INHIBITORY EFFECT OF ATRIAL-NATRIURETIC-FACTOR ON RENIN RELEASE INDUCED BY RENAL HYPOTENSION

To examine the effect of atrial natriuretic factor (ANF) on renin rele ase induced by renal hypotension, experiments were performed in seven barbiturate-anaesthetized dogs with denervated kidneys. Renin release induced by renal arterial constriction to 50 mmHg was measured before and during intrarenal infusion of ANF (200 ng min(-1) kg(-1) body weig ht). Before ANF infusion, renal arterial constriction increased renin release from 0.2 +/- 0.1 to 21.8 +/- 3.3 mu g angiotensin I min(-1) (p <0.05). During ANF infusion renal arterial constriction increased reni n release as much as before from 0.8 +/- 0.6 to 23.7 +/- 4.6 mu g angi otensin I min(-1) (p<0.05). Although ANF increased glomerular filtrati on rate from 33.9 +/- 4.2 to 43.4 +/- 5.6 ml min(-1) (p<0.05) and sodi um excretion from 72 +/- 22 to 567 +/- 112 mu mol min(-1) (p<0.05) at normal renal perfusion pressure, ANF was without effect on glomerular filtration rate and sodium excretion during renal arterial constrictio n. The present study shows that ANF is not an inhibitor of renin relea se induced by renal arterial constriction in anaesthetized dogs with d enervated kidneys. Our findings indicate that ANF does not influence r enin release induced by the haemodynamic mechanism.