Histopathological changes in WEHI-3B leukemia cells following intoxication by cytotoxin P4 from Naja nigricollis nigricollis venom.

The histopathological changes in WEHI-3B leukemia cells were followed by light and electronmicroscopy at different time intervals following exposure to cytotoxin P4 from Naja nigricollis nigricollis venom. At 1 hr after exposure to the toxin (2.5 x 10(-7) M) deformation was detected, primarily in the mitochondria, followed by vacuolization in the cytoplasm and an increase in lysosome number at 2 hr post-intoxication. Thereafter, the endoplasmic reticulum assumed a microsomal-like appearance, the plasma membrane was disrupted and, finally, the cells released their content to the culture medium. It is postulated that cytotoxin P4 may affect mitochondria either indirectly, by stimulating intracellular processes after binding to the cell membrane, or directly by interaction with the mitochondria after penetrating into the cell.