Chronic effects of dietary fumonisin on the heart and pulmonary vasculature of swine.

Fumonisins, mycotoxins produced in Fusarium moniliforme-infected corn, are hepatotoxic in several species and induce hepatocarcinomas in laboratory rats, leukoencephalomalacia in equine species, and fulminant pulmonary edema in swine. To date, the effects of fumonisin on pigs has dealt solely with the high levels required to induce the dramatic development of acute fulminant, and usually lethal, pulmonary edema. Less sensational, but equally important, are the chronic effects of fumonisin on swine health. In the first trial, six gilts were fed, ad libitum, a formulated complete ration containing 100 mg fumonisin B1 (FB1)/kg for 10 days followed by a ration containing 190 mg FB1/kg for up to 83 days. In the second trial, five gilts were fed, ad libitum, rations containing 150-170 mg FB1/kg for up to 210 days. The concentration of fumonisin B2 (FB2) was 31 +/- 2% that of the FB1. Weight-matched controls were selected for cardiac parameter comparison. Pigs fed fumonisin for at least 93 days developed nodular hyperplasia of the liver. Evidence from the microscopic examination of heart and lungs and gravimetric measurements of cardiac tissues from four pigs exposed to dietary fumonisins for 6 months suggests that the pulmonary vasculature is a target of chronic exposure. This study provides additional evidence linking the pathogenesis of fumonisin-induced lesions in a variety of organ systems of various animal species to a vascular mechanism.