Comparison of histopathologic effects of carnitine and ascorbic acid on reperfusion injury

Objective: Reperfusion injury can be seen after acute arterial occlusion, a cute myocardial infarctus and during open heart surgery and vascular surger y. Protective effects of ascorbic acid and carnitine on reperfusion damage were tested and compared using histopathologic examination on ischemia mode l in the rabbit hind limb. Methods: Four groups (each containing ten animal s) were used. In group I (G1), only anesthesia was administered and a biops y was taken from the soleus muscle after 6 h. In group II (G2), group III ( G3), and group IV (G4), after induction of anesthesia, arterial blood circu lation of right posterior extremity was blocked by a tourniquet proximally. After four hours of ischemia, just before releasing of tourniquet, physiol ogic saline solution, sodium ascorbate (Redoxan) and L-carnitine (Carnitine ) were administered intravenously to G2, G3 and G4, respectively. Following 2 h of reperfusion, biopsies were taken from soleus muscles. All of the bi opsy slides were observed under the light microscope from the aspect of six different histopathologic criteria (loss of striation, nuclear centralisat ion, formation of ring and/or splitting, changing on diameters of muscle fi bers, necrosis and minimal fibrosis) of ischemic muscle. Results: Ischemic change criteria were seen less frequency in both vitamin C and carnitine gr oups compared to the control and placebo groups. However, this protective e ffect was statistically significant only for the aspect of segmental necros is, centralization of nuclei and diameter change parameters in G3 and in G4 . When G3 and G4 were compared, the differences on protective effects were significant only from the aspect of fibrosis (P < 0.001) and changing on di ameter of the fibers (P < 0.001). Conclusions: Both sodium ascorbate and ca rnitine are effective on reducing the reperfusion injury in skeletal muscle . But when we compared these two agents to each other, we found that carnit ine seems a little more protective on our experimental model. (C) 2001 Else vier Science B.V. All rights reserved.