Cardiovascular effects induced by polymeric 3-alkylpyridinium salts from the marine sponge Reniera sarai

► Polymeric 3-alkylpyridinium salts (poly-APS) exert various biological activities by forming large pores in cell membranes. ► Poly-APS have direct dose- (1 nM-10 μM) and time-dependent (5-60 min) toxic effects on the cardiovascular system. ► Poly-APS diminished vascular function of the isolated rat aorta, and exerted cardiotoxic effects on the isolated rat heart. ► Poly-APS showed only minor toxicity in the low concentration range (1-10 nM).