Cyclosporine nephrotoxicity in rats with an acute reduction of renal function.

The early interactive nephrotoxicity of cyclosporine was studied in rats immediately after either unilateral nephrectomy or a combination of temporary renal ischemia and contralateral nephrectomy. Cyclosporine was administered intramuscularly (IM) for 4 weeks. In comparison to vehicle-treated animals, the rats receiving cyclosporine showed neither the compensatory increase in glomerular filtration rate after unilateral nephrectomy nor the recovery of function after renal ischemia. It is concluded that cyclosporine interferes with the normal compensatory response resulting from an acute loss of renal function. This could be due to an interaction with renal hemodynamics or hormonal factors mediating the compensatory renal response.