[Observations on cytolysis by cobra venom. Effect of sucrose loading]

LS cells cultivated for 4 days in sucrose-containing medium (Su) are more fragile than cells cultivated in medium devoid of this sugar (TN) when they are incubated with Naja-Naja venom; in fact the 51Cr radioactivity released into the medium by previously labelled cells is increased for the sucrose ones. Phospholipase does not seem to contribute to the lytic activity of the venom, which is dependent on the direct lytic factor: neither varying the temperature of incubation nor adding EDTA to the incubation medium modifies the results. Adding Ca++ decreases the 51Cr radioactivity released particularly by the cells grown in TN, suggesting a stabilizing action of this cation.