Potential Renoprotective Effects of Eplerenone and Captopril in L-Name-Treated Rats

In this study, we examined the renoprotective effects of curative and prophylactic doses of eplerenone and captopril in L-NAME-treated rats. Rats were divided into seven groups: The first and second (normal control and hypertensive control) groups received distilled water and L-NAME (L-nitro arginine methyl ester, 50 mg/kg per day), respectively, for eight weeks. The third and fourth groups received L-NAME (50 mg/kg per day) plus a prophylactic dose of eplerenone (50 mg/kg per day) or captopril (25 mg/kg per day), respectively, for eight weeks. The fifth, sixth and seventh groups received L-NAME (50 mg/kg per day) for eight weeks, followed by curative doses of eplerenone (100 mg/kg per day), captopril (50 mg/kg per day) or eplerenone plus captopril (50 + 25 mg/kg per day), respectively, for five weeks. The drugs were administered by gastric gavage. During prophylactic therapy, eplerenone and captopril decreased the L-NAME-induced rise in systolic blood pressure (SBP) and serum creatinine levels. Furthermore, both drugs improved microalbuminuria and renal histopathological changes and increased serum nitric oxide (sNO) levels. During curative therapy, eplerenone improved microalbuminuria and renal histopathological changes. Captopril or the combination of captopril and eplerenone improved all L-NAME-induced changes. The combination improved renal histopathological changes more significantly than each individual drug did. In conclusion, eplerenone and captopril have prophylactic and curative renoprotective effects in L-NAMEtreated rats, indicating the promising role of eplerenone as an add-on therapy to captopril in antihypertensive drug regimens.