[Effects of mycophenolate mofetil in ischemic acute renal failure in rats].

Mycophenolate mofetil (MMF) is a purine synthesis inhibitor commonly used as immunosupresive agent in transplantation. Kidney grafts undergo more or less prolonged cold ischemia after harvesting which results in variable degrees of ischemia reperfusion injury. To determine whether the inhibition of early events of cellular infiltration may influence the severity of damage induced by ischemic acute renal failure, 45 Sprague Dawley rats were given MMF at a dose of 20mg/kg/day (MMF-rats) by gavage 2 days before (pre-MMF group, n=15) or after (post-MMF group, n=15) clamping the left renal artery for 40 minutes followed by rigt-sided nephrectomy. (control group, n=15) received vehicle. Serum Creatinine (Screat) was measured daily in all groups. On the 2nd post-ischemic day Screat was significantly lower (p=0.001) in pre-MMF group compared with post-MMF group and control group (4 +/- 2mg/dl post-MMF group vs 1.7 +/- 1.2 mg/dl pre-MMF group, control group 5+/-2, p< 0.05). Kidney biopsies shown that the histologic damage was 54 +/- 28% in post-MMF group vs 34+/- 22% in pre-MMF group and 61 +/- 25% in control group (pre-MMF vs post-MMF, p NS). On the 5th day post-ischemic, MMF-rats showed more severe tubulointerstitial necrosis (pre-MMF group: 17 +/- 20 %, post-MMF group: 33 +/- 27%) than controls (4 +/- 5%). The severity of ATN was significantly higher in post-MMF group compared with controls (p=0.01). Tubulointersticial T-lymphocyte (T CD 5) and monocyte (ED 1) infiltration evaluated on the 2nd post-ischemic day was less intense in group I (T CD5: 3 +/- 3, ED 1: 10 +/- 9, cel/mm2) compared to post-MMF group (T CD 5: 10 +/- 4, ED 1: 55 +/- 40) and to control group (T CD 5: 10+/- 4, ED 1: 64 +/- 46). However, on the 5th post-ischemia day, ED 1 infiltration was significantly higher in post-MMF group (24 +/- 18%) compared to pre-MMF group (5 +/- 5, p NS) and also in pre-MMF group vs control group (31 +/- 33, p< 0.05). Our results suggest that MMF given before a renal ischemic insult may reduce the severity of histologic damage resulting from ischemia reperfusion injury.