Hypertension in rats induced by renal grafts from renovascular hypertensive donors

Abstract

Renal transplantations were performed, using microsurgical techniques, with adult male two-kidney, one clip hypertensive rats (n=9) and sham-operated normotensive Wistar-Kyoto rats (n=8) as kidney donors and with F1 hybrids, bred from Wistar-Kyoto and stroke-prone spontaneously hypertensive rat parents, as recipients. Systolic blood pressure before surgery was 200±2.7 mm Hg in hypertensive and 115±1.7 mm Hg in normotensive donors and 144±7.1 and 138±3.5 mm Hg in the two groups of recipients. Renal hypertension in donors was maintained for 14 weeks before surgery was performed and the nonischemic kidneys were transplanted. Bilaterally nephrectomized recipients of renal grafts from hypertensive donors developed sustained hypertension (185±3.9 mm Hg). In contrast, in recipients of renal grafts from normotensive donors, blood pressure decreased significantly to the level of the donors (111±3.7 mm Hg). Posttransplantation hypertension in recipients of renal grafts from hypertensive donors was associated with intrarenal vascular hypertrophy, smaller kidneys, a decreased glomerular filtration rate, an increased plasma urea concentration, and polydipsia as compared with normotensive transplanted controls. Renal pyelograms revealed no gross anatomic alterations of transplanted kidneys. Our data indicate that secondary damage to the renal grafts caused by high perfusion pressure before transplantation can induce hypertension in recipients of these kidneys. Furthermore, our data suggest that renal mechanisms may be necessary to maintain borderline hypertension in F1 hybrids.