NUTRIENT SUPPLEMENTATION PROTECTS CULTURED CHICKEN-EMBRYO SKELETOMYOCYTES FROM CYTOTOXICITY OF MONILIFORMIN AND OXYTHIAMINE

Basal Medium 199 supplemented with 100 mu M Of pyruvate, alpha-ketoglu tarate, thiamine or thiamine pyrophosphate (substrates and cofactor of alpha-ketoacid dehydrogenases) or 10 mM of glucose or fructose were t ested for the nutrient's ability to protect cultured primary chicken e mbryo skeletomyocytes from the cytotoxicity of moniliformin (a mycotox in) and oxythiamine (a thiamine antagonist) after 48 hr exposure. Supp lemented thiamine or its pyrophosphate completely inhibited the cytoto xicity of oxythiamine, but had no effect on the cytotoxicity of monili formin, supporting that oxythiamine is a thiamine antagonist and monil iformin is not an anti-thiamine factor. Supplemented glucose and fruct ose either negated or protected the cells from the cytotoxicity of mon iliformin and oxythiamine while supplemented alpha-ketoacids offered n o protection, suggesting cellular energy depletion as a cause of cell death. Moniliformin increased a dose-dependent depletion of glucose an d accumulation of pyruvate and lactate in culture supernatant, further supporting the cellular energy depletion as a mechanism of cell death caused by moniliformin. (C) 1997 Elsevier Science Inc.