Atorvastatin improves the course of ischemic acute renal failure in aging rats

Statins increase the production of nitric oxide (NO) and have beneficial effects on the course of acute renal failure (ARF) in young rats. The effects of a short-term treatment with atorvastatin (ATO) on ischemic ARF in old rats, characterized by a great susceptibility to ischemia, was tested. No difference was found in renal dynamics between young (Y, 3 mo old) and old (O, 18 mo old) rats in normal conditions (CON) or after ATO treatment (12 mg/kg/d for 14 d). Twenty-four hours after clamping of both renal arteries, a more pronounced decrease in GFR was observed in O rats versus Y rats after a greater renal vasoconstriction and hypoperfusion of aging animals. Pretreatment with ATO mitigated renal vasoconstriction in O rats and restored GFR values to Y rats. Nitrate excretion was enhanced in Y rats after ARF but was not further modified by ATO; in O rats, ARF did not increase nitrate excretion, which was raised after ATO treatment. This reflected the increase in endothelial NO synthase (eNOS)-mRNA expression and eNOS protein observed in old ATO-treated animals with ARF. ATO treatment had also a significant protective effect against the cell injury at tubular level in O, but not Y, rats. The Ras system was not influenced by ATO in O rats, whereas the activation of Rho proteins was partially inhibited by ATO. Low-dose treatment with ATO enhances NO availability in aging rats, improving renal dynamics and conferring a peculiar histologic protection at tubular level after ischemia.