Mechanism of renin release following furosemide diuresis in rabbit.

MEYER, PHILIPPE, JOEL MENARD, NIC~LAS PAPANICOLAOU, JEAN-M. ALEXANDRE$LAUDINE DEVAUX,AND PAUL MILLIEZ. Mechanism of renin release following furosemide diuresis in rabbit. Am. J. Physiol. 215(4) : 908-915. 1968.-Injection of furosemide (10 mg/kg, iv) into rabbits increased plasma renin activity within 7 min; plasma renin activity increased further throughout the course of the experiment and rvas associated with a moderate reduction of blood pressure, of plasma sodium concentration, and a marked contraction of plasma volume. A concomitant increase of extracellular fluid with isotonic saline infusion or of plasma volume with infusion of salt-poor albumin reduced the furosemide-induced renin secretion. Prevention of urinary losses by shunting urine into the femoral vein did not alter the furosemide-induced renin secretion despite the constancy of blood pressure, plasma sodium concentration, and plasma volume; the rise of plasma renin activity was, however, prevented when extracellular or plasma volume expansion was combined with reinfusion of urine. There was no specific relationship between changes in GFR and in plasma renin activity, although the data suggest a possible inverse correlation in the extreme upper ranges of both parameters. It is concluded that: a) furosemide-induced renin release is induced by some intrarenal mechanism, possibly by the increase of intratubular sodium concentration, b) plasma or extracellular fluid expansion counteracts the renin-stimulating effect of furosemide, and c) the renin-angiotensin system may have a regulating effect on glomerular filtration rate.