Influence of dose level and methionine intake on the effects of linamarin administration to rats.

Rats were fed a semipurified diet providing 10% casein supplemented with methionine for 2 wk, at which time some animals received the same diet without the methionine for 4 d. Animals that received linamarin were given a single oral dose containing 500 or 250 mg per kilogram of body weight. At the higher linamarin dose all animals died within 5 h after dosing. Biochemical and physiological changes observed in these rats included severe metabolic acidosis, decreased cytochrome oxidase activities, atrial fibrillation, and decreased respiratory rates. In general, the cardiac adenosinetriphosphatase enzymes were inhibited by linamarin. None of these changes were moderated by dietary methionine supplementation. At the lower linamarin dose dietary supplementation with methionine appeared to reduce incidences of clinical toxicity signs and fatalities. No methionine effect was observed in the other biochemical and physiological measurements in rats given this amount of linamarin. The results suggest that dietary supplementation with methionine provided some protection against the toxicity of the lower level of linamarin administered.