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Molecular Mechanisms Of Physalia Physalis Venom Modulation Of Cardiac And Vascular Functions, Eva Luo

Loma Linda University Electronic Theses, Dissertations & Projects

Portuguese man-of-war (Physalia physalis)venom has profound effects on the cardiovascular system of man and animals. The venom produces vascular relaxation in norepinephrine precontracted, intact rabbit femoral arterial rings by stimulating vasodilatory prostaglandin synthesis in the endothelium. This action does not depend on endotheliumderived relaxing factor (EDRF). P. physalis venom produces a vascular constriction on KC1 depolarized, intact rings. This is completely inhibited by dibenzyline and yohimbine. Increased membrane permeability to calcium may be involved in direct vascular smooth muscle stimulation. The venom has a positive inotropic effect on rat atrial preparations, which is intensified by increased extracellular calcium concentration. …