[Effects of Bitis gabonica venom on heart dynamics and circulatory resistance in the rabbit]

The effect on the cardiovascular system of intravenous injections of Bitis gabonica venom was studied on 10 urethan anesthetized rabbits, by giving the venom in three successive doses of .125 (I Dose), .250 (II Dose) and .500 (III Dose) mg/kg. In partial agreement with already reported data, the results of our experiments showed a powerful but transient fall of total peripheral resistance, which seemed to be relatively independent of doses. A cardiotoxic action leading to severe reduction of cardiac output was also found, but only at the II Dose; this effect was apparently irreversible, and was not enhanced by the III Dose. Moreover, a prompt bradicardic effect after each administration was found, which may not be attributed to direct effects of the venom on the cardiac pacemaker cells.