Nephrotoxic action of rattlesnake and sea snake venoms: an electron-microscopic study

The fine structure of renal corpuscles and proximal convoluted tubules of the right kidneys of Suiss mice were studied 9 hr after the injection of the venom of Crotalus atrox (Western diamond-back rattlesnake) or the venom of Laticauda semifasciata (broad-banded blue sea snake). Rattlesnake envenomation resulted in several ultrastructural changes in the renal corpuscles and proximal convoluted tubules. Visceral epithelial changes included intracellular oedema, blebbing, vesiculations, the formation of microvillus projections and dilatation of the endoplasmic reticulum and mitochondria. Changes in the parietal epithelium were similar except that no microvillus projections were noted. Mesangiolysis was a consistent finding. Collagenous fibrils were very prominent in the lysed areas of the mesangial cells. Increased numbers of lysosome-related structures were noted in the proximal convoluted tubule cells. Most of the nuclear cisternae of the cells of the renal corpuscles and proximal convoluted tubules were greatly dilated. Sea snake envenomation resulted in focal organellar swelling and focal intracellular oedema of the visceral epithelium. This venom did not affect the cells of the proximal convoluted tubule. The presence of light and dark visceral epithelial cells has been a consistent finding for both the control and the environmated groups.