L-Carnitine and its Protective Role in Contrast-Induced Renal Injury in Rats

Contrast media-induced nephrotoxicity is one of the most common causes of acute renal failure and promotes both increased morbidity and greater healthcare costs. several mechanisms by which contrast media induces renal injury. These include renal vasoconstriction and direct effect of the contrast agents and reactive oxygen metabolites production. L-carnitine facilitates the transfer of long-chain fatty acids into the mitochondria. By this mechanism carnitine maintains low pools of fatty acid (acyl)-coenzyme a compounds, which are potentially toxic. However some of the actions of L-carnitine may be opposite to the toxic effects of contrast media. This study examined wheter administration of L-carnitine ameliorates contrast media-induced renal injury in rats. Fifty Sprauge-Dawley rats, weighting 140-230 gr were assigned to one of five treatment groups: group A(control) rats were given normal saline injections daily for 4 consecutive days, group B rats were given contrast media(diatrizoate meglumine) 1cc/kg/d, group C rats were given meglumine 1cc/kg/d and carnitine 200mg/kg/d, group D rats were given meglumine 1cc/kg and carnitine 80mg/kg/d, and group E rats were given carnitine 200mg/kg/d. Four days after injections, the rat were killed and their kidneys and blood samples were prepared for pathological and biochemistry examination. Histological scoring of renal cortical pathology was performed. In rats that were given meglumine and no carnitine, renal function tend to be lower than in control group (p =0.001). Among rats injected with meglumine, those given 200mg/kg/d of L-carnitine had higher creatinine clearances at day 4 than the rats not given carnitine (p =0.004). Renal cortical histopathology changes were milder with meglumine and L-carnitine, particularly at 200mg/kg/d. In rats receiving meglumine, daily L- carnitine injections, particularly at 200 mg/kg ameliorates the severity of renal cortical proximal tubular necrosis and maintain greater renal function.