ANTAGONISTIC EFFECT OF SE ON THE T-2 TOXIN-INDUCED CHANGES IN THE ULTRASTRUCTURE AND MITOCHONDRIAL-FUNCTION OF CULTURED CHICKEN EMBRYONIC CHONDROCYTES

T-2 toxin extracted from a strain of Fusarium tricinctum has a structure similar to that of the Fusarium mycotoxin found in grains in Kaschin-Beck Disease endemic areas. By scanning and freeze-fracture transmission electron microscope observations, we found that 0.01 ppm T-2 toxin caused a significant decrease of collagen microfibrils in the extracellular matrix and intramembrane particles on the protoplasmic face of the plasma membrane of cultured chicken embryonic chondrocytes. In addition, T-2 toxin obviously reduced the activities of mitochondrial cytochrome c oxidase and H+-ATPase, and the sensitivity of the latter to oligomycin, of chondrocytes. In our experiment we found that, when 0.01 ppm T-2 toxin was added in the presence of 1 ppm Na2SeO3 in the culture; the decreases in collagen microfibril and intramembrane particle numbers could not be seen and that the activities of cytochrome c oxidase and H+-ATPase and the sensitivity of the latter to oligomycin were less decreased. Furthermore, the experimental result showed that the effect of Se on chondrocytes is concentration dependent and that 1 ppm of Na2SeO3 is the optimal concentration. Thus we conclude that Se deficiency may be an important factor for the pathogenesis of Kaschin-Beck disease.