EFFECTS OF VARYING SODIUM INTAKE ON BLOOD-PRESSURE AND RENIN-ANGIOTENSIN SYSTEM IN SUBTOTALLY NEPHRECTOMIZED RATS

  • 1 January 1976
    • journal article
    • research article
    • Vol. 88  (5) , 807-816
Abstract
The effects of varying Na intake on blood pressure [BP], serum electrolytes, renin-angiotensin system and some other parameters that were modified simultaneously were studied in rats in which the renal mass had been reduced by 70%. Within 4 wk, a high Na diet (750 meq/kg) resulted in marked hypertension, whereas a standard Na diet (250 meq/kg) elevated the BP only slightly. A low Na diet (< 0.2 meq/kg) prevented the rise in BP. In the hypertensive and intravascular spaces. The compensatory renal hypertrophy was accelerated by the high Na diet and retarded during Na restriction. During low Na intake, the serum concentration of Na was diminished and that of K elevated. During the high Na diet, the Na concentration was unchanged, but the K concentration was decreased. Subtotal nephrectomy diminished the plasma angiotensin II concentration and the renin content of the kidney remnant was lower than that of the kidneys from control animals. Na restriction stimulated the renin-angiotensin system markedly, whereas high Na intake suppressed it. After subtotal nephrectomy, elevation of BP, renal hypertrophy and suppression of the renin-angiotensin system are closely related to Na intake.