Glycerol-induced acute renal failure in the rat: The protective effect of unilateral nephrectomy

Studies were performed to evaluate the effect of unilateral nephrectomy on glycerol-induced acute renal failure in the rat. Normal rats were subjected to either sham uninephrectomy (n = 43) or right uninephrectomy (n = 53). The functional compensation of the remaining kidney was followed after 1 and 2 weeks. Fourteen days after the operation, acute renal failure was induced by injection of 50% glycerol solution to both groups. Uninephrectomised rats developed a lesser degree of renal failure compared to sham-operated rats. Forty-eight hours after glycerol injection, P_Cr of uninephrectomised rats was 260 ± 22 μmol/1 compared with 338 ± 26 in sham-operated rats (P< 0.0125) and C_Cr in uninephrectomised rats was greater (0.10 + 0.01 ml/min vs 0.07 ± 0.01; P< 0.025) in sham rats. Uninephrectomised rats had significantly greater recovery of C_Cr compared to sham rats at 24 h (20.1% ±2.3 vs 13.1% +2.2, P<0.025) and at 48 h (32.1 % ± 3.3 vs 19.2% ±3.3, P<0.005) after glycerol injection. FENa was significantly less in uninephrectomised rats: 0.96±0.16% vs 2.25±0.05% (P<0.025) in sham rats 24h post glycerol. Urinary excretion of K⁺ was greater in rats following uninephrectomy compared to sham rats both after 24 h and 48 h post glycerol (P<0.01), accompanied by lower plasma potassium (P<0.05). A correlation coefficient (r) of 0.793 was observed between urinary potassium excretion rate and percentage recovery of C_Cr. Renal failure was characterised by oliguric and non-oliguric forms, oliguria was significantly less frequent in uninephrectomised rats: 20.8% vs 37.2% (P<0.05) in sham rats. Our results show that unilateral nephrectomy for 2 weeks with a nearly full functional compensation of the remaining kidney, confers partial protection against glycerol-induced acute renal failure.