Sodium homeostasis in transplanted rats with a spontaneously hypertensive rat kidney

Sodium homeostasis in transplanted rats with a spontaneously hypertensive rat kidney. Am J Physiol Regulatory Integrative Comp Physiol 279: R1099-R1104, 2000.--Recipients of a kidney from spontaneously hypertensive rats (SHR) but not from normotensive Wistar-Kyoto rats (WKY) develop posttransplantation hypertension. To investigate whether renal sodium retention precedes the development of posttransplantation hypertension in recipients of an SHR kidney on a standard sodium diet (0.6% NaCl), we transplanted SHR and WKY kidneys to SHR X WKY F1 hybrids, measured daily sodium balances during the first 12 days after removal of both native kidneys, and recorded mean arterial pressure (MAP) after 8 wk. Recipients of an SHR kidney (n = 12) retained more sodium than recipients of a WKY kidney (n = 12) (7.3 [+ or -] 10 vs. 4.0 [+ or -] 0.7 mmol, P [is less than] 0.05). MAP was 144 [+ or -] 6 mmHg in recipients of an SHR kidney and 106 [+ or -] 5 mmHg in recipients of a WKY kidney (P [is less than] 0.01). Modest sodium restriction (0.2% NaCl) in a further group of recipients of an SHR kidney (n = 10) did not prevent posttransplantation hypertension (MAP, 142 [+ or -] 4 mmHg). Urinary endothelin and urodilatin excretion rates were similar in recipients of an SHR and a WKY kidney. Transient excess sodium retention after renal transplantation may contribute to posttransplantation hypertension in recipients of an SHR kidney. hypertension; transplantation