l‐carnitine ameliorates gentamicin‐induced renal injury in rats

Background. This study examined whether administration of L-carnitine ameliorates gentamicin-induced renal injury in rats. Methods. Male Sprague–Dawley rats were assigned to one of seven treatment groups: group A (control) rats were given normal saline injections daily for 8 consecutive days; group B, C and D rats were given gentamicin injections, 50 mgukg body weightuday daily for 8 consecutive days; and group E, F and G rats were given gentamicin injections, 80 mgukguday daily for 8 consecutive days. Starting 4 days before these injections, all groups were given additional injections, for 12 consecutive days, of normal saline (groups A, B and E) or L-carnitine at 40 mgukg (groups C and F) or 200 mgukg (groups D and G). Histological scoring of renal cortical pathology was performed after day 12. Results. Among rats injected with gentamicin 50 mgukguday, those given either 40 or 200 mgukguday of L-carnitine had higher creatinine clearances at day 12 than the rats not given carnitine. In the rats given 80 mgukg gentamicin and no carnitine, renal function tended to be lower than in controls. At day 12, the rats given gentamicin 80 mgukg and L-carnitine 200 mgukguday, compared with rats given gentamicin 80 mgukg and no carnitine, displayed lower serum urea and probably creatinine concentrations, and higher creatinine clearances, and their serum urea was not different from control (group A) rats. Both doses of gentamicin induced renal cortical histopathology. Changes were milder with gentamicin 50 mgukguday, and L-carnitine, particularly at 200 mgukguday, ameliorated the severity of renal pathology induced by both gentamicin doses. In rats given gentamicin 80 mgukguday, the animals treated with carnitine 200 mgukguday had significantly less severe proximal tubular necrosis and significantly greater mild proximal tubular necrosis compared with rats receiving L-carnitine 40 mgukguday or no carnitine. Conclusions. In rats receiving gentamicin, daily L-carnitine injections, particularly at 200 mgukguday, ameliorate the severity of renal cortical proximal tubular necrosis and maintain greater renal function.