Introduction

Tissue subjected to a period of ischemia undergoes damage (1,2). The purpose of the present study is to clarify the effects of ascorbic acid on renal I/R injury in rabbits.

Materials and methods

Fifteen New Zealand white rabbits weighing 2-4 kg were used for the experiments. In group 1 (n = 3), only the right kidney was removed. In group 2 (n = 3), the left kidney was freed from the perirenal tissue and fat after the right nephrectomy. A bolus of 150 IU/kg of heparin was given IV 3 minutes before ischemia and the left renal vessels were clamped with an atraumatic vascular clamp. After ischemia for 30 minutes, the clamp was removed and the blood reflows. In group 3 (n = 3), ascorbic acid 50 mg/kg IV before the operation. After ischemia during 30 minutes, then the renal vessels were unclamped. The right nephrectomy was performed. In group 4 (n = 3); ascorbic acid 100 mg/kg IV before the operation. In group 5 (n = 3); ascorbic acid 200 mg/kg IV before the operation.

Results

The levels of SOD were significantly increased in the group 4 and 5 at the 24 hours after reperfusion compare to group 2. The levels of GSHPx activities (nmol/min/ml) were measured. They were 143.20 ± 12.23 (group 1), 118.01 ± 2.81 (group 2), 125.268 ± 15.80 (group 3), 150.24 ± 13.77 (group 4) and 163.76 ±13.28 (group 5) followed by 24h reperfusion. The levels of CAT activities (nmol/min/ml) were measured. They were 9.19 ± 0.74 (group 1), 4.15 ± 1.49 (group 2), 5.74 ± 1.10 (group 3), 8.06 ± 0.77 (group 4) and 10.80 ± 1.79 (group 5) followed by 24h reperfusion.

Conclusion

Antioxidant enzyme activity suggests that premedicated ascorbic acid alone may have roles on the attenuation of I/R injury and recovery of renal function in rabbits.