Histological and ultrastructural changes of the kidney in renal failure after viper envenomation

Forty experimental animals injected with lethal doses of Russell's viper venom and seven human victims of viper snake bite were studied in order to elucidate the pathogenesis of renal tubular necrosis due to viper envenomation. Autopsy, light and electron microscopic examinations were performed on animals and on 4 patients that died; renal biopsy studies were also carried out on the 3 patients that recovered. General features of disseminated intravascular coagulation, consumption coagulopathy and paradoxic haemorrhage were seen as a result of the strong coagulant effects of the venom. The salient features in the kidney are intraglomerular deposition of fibrin, fibrin degradation products and coagulation. The obstruction of glomerular capillaries by coagulated material is the most likely cause of reduction of blood supply to the renal tubules. This tubular ischemia results in tubular necrosis and subsequent renal failure.