CARDIOVASCULAR-RESPONSES TO SHORT-TERM FUMONISIN EXPOSURE IN SWINE

The cardiovascular effects of the mycotoxin fumonisin were examined in male cross-bred pigs fed 20 mg/kg of fumonisin-containing culture mat erial for 7 days. On Day 8, pigs were anesthetized with halothane and surgically catheterized. Cardiovascular measurements and blood gas ana lyses were obtained during halothane anesthesia and 18 hr after recove ry from anesthesia. Pigs fed fumonisin had significant (p < 0.05) decr eases in maximal rate of change of left ventricular pressure, heart ra te, cardiac output, and mean aortic pressure, a significant increase i n mean pulmonary artery pressure and pulmonary vascular resistance, an d no change in left ventricular end-diastolic pressure, pulmonary wedg e pressure, and central venous pressure. Treated pigs also had signifi cant decreases in both arterial and mixed venous blood O-2 tension, an d systemic oxygen delivery, but significantly increased oxygen consump tion and oxygen extraction ratio. These results suggest that fumonisin increases oxygen consumption and is a negative inotropic and chronotr opic agent in pigs. Because fumonisin is a naturally occurring inhibit or of the enzyme sphingosine N-acyltransferase, thereby increasing sph ingosine concentrations in vivo, we speculate that the observed cardio vascular effects were mediated in part by a fumonisin-induced increase in tissue sphingosine concentrations. (C) 1996 Society of Toxicology