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

Abstract

Objective: Reperfusion injury can be seen after acute arterial occlusion, acute myocardial infarctus and during open heart surgery and vascular surgery. Protective effects of ascorbic acid and carnitine on reperfusion damage were tested and compared using histopathologic examination on ischemia model in the rabbit hind limb. Methods: Four groups (each containing ten animals) were used. In group I (G1), only anesthesia was administered and a biopsy 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 circulation of right posterior extremity was blocked by a tourniquet proximally. After four hours of ischemia, just before releasing of tourniquet, physiologic 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 biopsy slides were observed under the light microscope from the aspect of six different histopathologic criteria (loss of striation, nuclear centralisation, formation of ring and/or splitting, changing on diameters of muscle fibers, necrosis and minimal fibrosis) of ischemic muscle. Results: Ischemic change criteria were seen less frequency in both vitamin C and carnitine groups compared to the control and placebo groups. However, this protective effect was statistically significant only for the aspect of segmental necrosis, 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 diameter of the fibers (P < 0.001). Conclusions: Both sodium ascorbate and carnitine are effective on reducing the reperfusion injury in skeletal muscle. But when we compared these two agents to each other, we found that carnitine seems a little more protective on our experimental model. (C) 2001 Elsevier Science B.V. All rights reserved.