Ingestion of fumonisin B1-containing culture material decreases cardiac contractility and mechanical efficiency in swine

Fumonisins are mycotoxins produced primarily by Fusarium verticillioides, a fungus that commonly contaminates corn. Fumonisin ingestion increases plas ma and tissue sphingosine and sphinganine concentrations and causes porcine pulmonary edema, which has been attributed to acute left-sided heart failu re or increased vascular permeability. We investigated the effect of short- term ingestion of fumonisin B1-containing culture material on cardiac funct ion in pigs. Treated male pigs (n = 7) received fumonisin-containing cultur e material which was mixed into the grower diet at 20 mg fumonisin B1/kg bo dy weight each day, while control pigs (n = 7) were fed only the grower die t on the same schedule as the treated pigs, Pigs were anesthetized after 3 days of receiving either diet and instrumented to accurately characterize t he cardiovascular effects of fumonisin ingestion. Fumonisin-treated pigs ha d lower cardiac outputs and heart rates than control pigs. Fumonisin-treate d pigs also had a marked reduction in cardiac contractility, as indicated b y decreased values for end-systolic elastance (the gold standard in vivo me asure of cardiac contractility), V-0 (the intercept value for the end-systo lic pressure-volume relationship), and mechanical efficiency. These data in dicate that in pigs, short-term ingestion of fumonisin B1-containing cultur e material produces negative inotropic and chronotropic effects and decreas es mechanical efficiency of the left ventricle. Theses cardiovascular effec ts are consistent with fumonisin-induced, sphingosine-mediated L-type Ca2channel blockade and suggest that pulmonary edema in pigs fed fumonisin is primarily due to acute left-sided heart failure instead of increased vascul ar permeability. (C) 2000 Academic Press.