Species and organ specificity of fumonisin-induced endothelial alterations: Potential role in porcine pulmonary edema

Fumonisins, mycotoxins that commonly contaminate corn, induce cardiovascular toxicity and pulmonary edema in pigs, leukoencephalomalacia in horses, and nephropathy in rats, rabbits, and lambs. The mechanisms of these species-specific target organ toxicoses are poorly understood. We have previously reported perinuclear accumulation of membranous material in pulmonary capillary endothelial cells of pigs fed fumonisin-containing culture material. We hypothesized that these endothelial accumulations may be important in the pathogenesis of fumonisin-induced pulmonary edema and target organ toxicity in other species. Both target and non-target tissues from fumonisin-exposed pigs, sheep, rabbits, and rats were examined ultrastructurally. Specifically, lung, liver, heart and kidney were examined. In agreement with our previous work (Gumprecht, L.A., Beasley, V.R., Weigel, R.M., Parker, H.M., Tumbleson, M.E., Bacon, C.W., Meredith, F.I., Haschek, W.M., 1998. Development of fumonisin-induced hepatotoxicity and pulmonary edema in orally dosed swine: morphological and biochemical parameters. Tox. Pathol. 26, 777-788), endothelial alterations were present in the pulmonary capillary endothelial cells of pigs fed fumonisin-containing culture material, but at doses that did not induce pulmonary edema, as well as in pigs injected intravenously with purified fumonisin B₁. These alterations were present only in the pulmonary capillary endothelium of pigs and not in other species. In addition, these endothelial alterations were not present in any other organ of pigs or other species examined. Thus, these endothelial alterations are induced by fumonisin B₁, but only in pulmonary capillary endothelium and only in pigs. Although evidence that these alterations play a role in fumonisin-induced pulmonary edema is limited, other endothelial functions may be affected by fumonisin treatment.