Effects of Nematocyst Toxin of Physalia physalis (Portuguese Man-of-War) on the Canine Cardiovascular System.

Abstract

Nematocyst toxin from Physalia physalis, when injected intravenously into dogs, activated ectopic cardiac pacemaker centers and induced “re-entry” extrasystoles; these effects could be reversed by infusion of KCl. After injection of a fatal dose, these arrhythmias progressed into ineffectual ventricular beats and cardiovascular collapse. In addition to cardiac arrhythmias, sub-lethal doses of toxin caused increased systemic blood pressure and cardiac output, elevation of serum K, decrease of serum Na, elevated breathing rate, and hemolysis.