[Effects of atorvastatin on ischemic acute renal failure in aging rats]. / Effetti della atorvastatina nell'insufficienza renale acuta ischemica del ratto anziano.

ABSTRACT

BACKGROUND: Aging (O) rats have a greater susceptibility to renal ischemia than young (Y) rats due to an endothelial dysfunction partially reversed by exogenous administration of L-Arginine. Since statins are able to increase nitric oxide (NO) production, aim of the study was to evaluate whether pre-treatment with atorvastatin (ATO, 10 mg/kg/day for 12 days), had positive effects on ischemic acute renal failure (ARF) of aging rats. METHODS: Renal clearance studies (inulin) were performed 24 hours after ischemia in 6 Groups (n=6 in each Group) of both Y- and O-rats control rats (CON), untreated rats with ARF (Groups IRA), and rats with ARF but pretreated with ATO (Groups ATO+IRA). RESULTS: Renal ischemia determined a sharper decrease in GFR of Group O-IRA than Y-IRA (-80% and -63% vs respective CON, both p<0.001). In both Groups the fall in GFR was secondary to renal vasoconstriction and the consequent reduction in renal plasma flow. Pre-treatment with ATO did not modify GFR in Group Y-ATO+IRA, but was able to determine a marked rise in GFR of rats of O-ATO+IRA Group (+100% vs O-IRA), through a reduction in renal vascular resistances. Induction of ARF greatly enhanced nitrate excretion in Group Y-IRA, but slightly affected Group O-ARF. Administration of ATO did not modify nitrite excretion in Y rats, whereas it was able to increase nitrate excretion in O-ATO+ARF rats (+111% vs O-IRA). CONCLUSIONS: Pre-treatment with ATO is able to improve the renal response to ischemia in aging rats, through a mechanism which likely is NO-dependent.