Effects of Fumonisins on Cardiovascular Function in Swine

Fumonisins (FB), are a group of naturally occurring mycotoxins produced by the fungus Fusarium moniliforme. These toxic metabolites of corn have been implicated in field cases of porcine pulmonary edema (PPE). The mechanism of fumonisin-induced pulmonary edema in swine is currently unknown; however, it may be related to altered sphingolipid biosynthesis. It was recently discovered that fumonisins are naturally occurring inhibitors of sphingosine (sphinganine) N-acyltransferase. This enzyme is a key component in the pathway for sphingolipid biosynthesis. We previously reported that this fumonisin-induced enzyme inhibition results in increased concentrations of free sphinganine and sphingosine in the serum and tissues of swine, as well as a depletion of complex sphingolipids. Sphingosine is an important intracellular second messenger that participates in receptor interaction and signal transduction through modulation of various calcium channels, protein kinases, and calmodulindependent enzymes.