ABSORPTION AND ELIMINATION OF VIPER VENOM AFTER ANTIVENOM ADMINISTRATION

The mechanisms by which antivenom neutralizes the venom are still poor ly understood. In the present work, we studied the effects of antiveno m, constituted with either F(ab')(2) or Fab, on the processes of absor ption and elimination of Vipera aspis venom in experimentally envenome d rabbits. We first concluded from this study that during the few hour s after intramuscular injection, the venom rapidly disappeared from th e site of injection but did not immediately reach the vascular system, suggesting that it is paltry absorbed via the lymphatic circulation. Concerning the elimination process of the venom in the presence of ant ivenom, we observed that the elimination of F(ab')(2)/venom complexes is slower than that of free venom in the absence of antivenom but fast er than that of free F(ab')(2), suggesting that F(ab')(2)/venom comple xes are eliminated by phagocytosis. The Fab/venom complexes, on the ot her hand, are eliminated more slowly than free Fab. These complexes ar e not eliminated through the renal route in agreement with their high molecular weight. In addition, we observed that the treatment of enven omed rabbits with antivenom made of Fab, but not F(ab')(2), is respons ible for an oliguria that could be responsible for clinical problems.