Effect of mycotoxins on uptake and degradation of [125I] albumin in mouse liver and kidney lysosomes.

Some mycotoxins have been evaluated with respect to effects on the reticuloendothelial function of uptake and degradation of a soluble, denatured protein in phagolysosomes isolated from mouse liver and kidneys. Toxins were dissolved in dimethylsulfoxide and administered intraperitoneally. Particulate fractions isolated from liver and kidney homogenates were assayed for proteolytic activity within osmotically active particles (phagolysosomes). Treatment with citrinin, penitrem A, streigmatocystin, and zearalenone produced inhibition of proteolysis in kidney but not in liver phagolysosomes. Moniliformin and T-2 toxin had no detectable effect on lysosome formation or function in either tissue. The phagolysosomal toxicity of these compounds appeared to be more toward kidney than liver. Both sterigmatocystin and zearalenone caused an increase in kidney phagolysosomal fragility at early times after treatment, and all agents except penitrem A caused a decrease in uptake of labeled albumin into kidney cells. Citrinin labelized kidney phagolysosomes in vitro but not in vivo, while only citrinin and zearalenone inhibited in vitro preparations of cathepsin.