EFFECTS OF CYPROHEPTADINE ON PLASMA SUPEROXIDE-DISMUTASE ACTIVITY ANDMALONDIALDEHYDE CONTENT IN RABBITS WITH HEMORRHAGIC-SHOCK

Profound hemorrhagic shock was produced in thirty rabbits by exsanguin ation via the carotid artery until blood pressure (BP) reached 5.3 kPa (40 mmHg) and was sustained for a period of 90 minutes. The rabbits w ere equally divided into cyproheptadine (Cyp) treated group and contro l group. Blood samples 30 minutes after liquid and blood infusion and administration of Cyp (10 mg/kg) were collected from the carotid arter y, and the plasma superoxide dismutase (SOD) activity and malondialdeh yde (MDA) content measured. The results showed that Cyp remarkebly enh anced the plasma SOD activity (2462 +/- 338 vs 1955 +/- 596, P < 0.01) and reduced MDA content (2.68 +/- 0.24 vs 3.20 +/- 0.49, P < 0.01). W e believe that the increase of O2 production plays an important role i n the development of shock, the single blood and liquid infusion can n ot significantly improve the shock conditions. Scavenging oxygen free radicals and alleviating cellular damage and multiple organ failure ar e the possible mechanisms of cyproheptadine anti-shock effect.