Diminution of antidiuretic and natriuretic response to arginine vasopressin in rats with five-sixths nephrectomy

Abstract

Adult male Sprague-Dawley rats subjected to five-sixths nephrectomy (5/6NX) and uninephrectomy (UNX) were tested for their responses to arginine vasopressin (AVP) at a rate of 100 microunit/kg/min during water diuresis. Blood and timed urine samples were collected for determination of inulin, creatinine, urea nitrogen, osmolality and sodium. The levels in plasma of urea nitrogen and creatinine were greater in 5/6NX than in intact or UNX group. Antidiuretic response to AVP diminished with intensity of renal ablation. The increased urine osmolality in response to AVP was also found to attenuate with varying degrees of nephrectomy. Marked natriuretic response to AVP was observed in intact and UNX rats but not in the 5/6NX group. In conclusion, diminished antidiuretic and natriuretic response to AVP in rats with 5/6NX might be the results of alteration of lower segments of remnant nephron secondary to uremia following extensive renal ablation.