Protective effects of L-carnitine on myocardium of experimentally diabetic rats with additional ischaemia and reperfusion

We investigated the protective effects of L-carnitine against damage to the heart caused by diabetes-induced alterations and additional ischaemia and reperfusion in diabetic BB/OK rats using histological techniques, morphometry, biochemical parameters of oxidative stress, and SOD expression. The results revealed that diabetes-induced morphological changes were partly improved or nearly prevented by substitution of L-carnitine, which also seemed to improve the reduced tolerance of diabetic myocardium towards ischaemia/reperfusion with respect to morphological parameters. Immunohistochemical and biochemical parameters of oxidative stress such as SOD protein expression as well as SOD and GPx activity indicate increased free oxygen radical level in the ischaemic/reperfused diabetic myocardium, which is clearly decreased by L-carnitine treatment. We suggest that L-carnitine may be an adequate "causal" agent in the protection of myocardial alterations in diabetes with additional ischaemia and reperfusion, as it stabilizes mitochondrial and cellular function and acts through its antioxidative or radical scavenging potential. Further investigations are necessary to determine an approach towards adjuvant treatment of diabetic myocardial complications using L-carnitine.