THE EFFECT OF COBALT CHLORIDE ON SKIN FLAP SURVIVAL

The effects of cobalt chloride on ischaemia-reperfusion injury were ev aluated in skin flaps. Groin neurovascular island flaps, 3 x 6 cm, wer e elevated in rats and subjected to primary and secondary ischaemia. P rimary ischaemia was produced by 1 hour occlusion of the femoral arter y and vein and, 22 hours later, secondary ischaemia was produced by 3 hours venous occlusion. The treatment group received intraperitoneal c obalt chloride (5 or 10 mg/kg) at the time of secondary ischaemia. Fla p survival was 80% in the control, 10 to 20% in the cobalt chloride tr eated, and 20% in the cobalt plus mannitol group. Mannitol (100 mg/kg) failed to prevent the harmful effects of cobalt. Skin flaps exposed t o cobalt chloride exhibited increased thiobarbituric acid reactant (TE AR) levels of 20 to 30 times normal. Of the antioxidant enzymes, gluta thione peroxidase activity increased by 40% (P<0.01), whereas glutathi one reductase activity decreased by 40% (P<0.01) in the cobalt exposed groups. Glucose 6-phosphate dehydrogenase activity was not affected.