Some pharmacological properties of the venom, venom fractions and pure toxin of the yellow-bellied sea snake Pelamis platurus.

The effects of the crude venom, four partially purified venom fractions and pure toxin (Pelamis toxin alpha) from yellow-bellied sea snake, Pelamis platurus, on respiration, blood pressure, heart and skeletal muscle of rabbits have been examined. Results indicated that crude venom, a partially purified toxic fraction and Pelamis toxin alpha caused initial respiratory stimulant effects followed by respiratory paralysis. In most cases, respiratory paralysis occurred before a profound fall in arterial pressure. Depression of the twitch response to nerve stimulation was observed in the tibialis anterior muscle. No significant change in the electrocardiogram was seen. Three partially purified non-toxic fractions of the crude venom induced transient respiratory stimulant effects. It was concluded that the crude venom and Pelamis toxin alpha had an identical mode of action and that they caused respiratory paralysis in rabbits.