The antagonistic effect of L-cysteine in experimental hymenoxon intoxication in sheep

L-Cysteine was given IV at dosages of 34.5, 48.8, 69.0, 97.6, or 138.0 mg/kg of body weight to groups of sheep previously treated (10.6 minutes) intraperitoneally with an LD92 of hymenoxon (12.8 mg/kg). L-Cysteine at dosages of 69.0, 97.6, and 138.0 mg/kg significantly increased survival rate 8.4-, 10-, and 12.5-fold, respectively, over that of gymenoxon-treated sheep not given L-cysteine. L-Cysteine at dosages of 34.5 and 48.8 mg/kg failed to significantly reduce mortality. Surviving hymenoxon-treated sheep given 97.6 or 138.0 mg of L-cysteine/kg showed mild or no clinical signs of toxicosis. There was no dosage of L-cysteine that significantly changed the survival time for fatally intoxicated sheep.