Effect of cyclosproin a upon compensatory renal hypertrophy combined with ishemic injury in a pair feeding rat model

Cyclosproin A (CyA) is a potent immunosuppressive agent which has a unique mode of action. It has been widely used in organ transplantation and has improved graft survival. However, a patiental harmful side effect, nephrotoxicity has been reported, by a number of investigators clinically and experimentally. The mechanism of this toxicity is still controversial. The purpose of this study is to test the affect of CyA on compensatory renal hypertrophy when the kidney is exposed to ischmia, utilizing a pair feeding model to minimize the effect to diet. The rats were divided into following four groups. Group 1 : nephrectomy only, group 2 : nephrectomy plus CyA, group 3 : nephrectomy olus ischemia, group 4 : identical to group 3 except CyA was administered. Forty five minutes of warm ischemia or simple expose was made on the remaining kidneys. All were pair fed. Rats of each group were given CyA 50mg/kg or vehice orally for eleven days. After the renal blood flow and the renal function were given CyA 50mg/kg or vehicle orally for eleven days. After the renal blood flow and the renal function were determined on day eleven, rats were sacrified and kidneys were removed and weighed. In coonclusion, the renal function significantly deteriorated in the CyA groups with or without ischemia and worse in the group with ischemia. However, kidney growth and renal blood flow were suppressed significantly only in group 4 compared to group 3. A synergic harmful effect of CyA and ischemia on compensatory renal hypertrophy was suspected.