Establishment of animal model for elucidating the mechanism of intoxication by the poisonous mushroom Clitocybe acromelalga

Dietary intake of a poisonous mushroom, Clitocybe acromelalga, causes acromelalgia. The symptom continues for over a month. Some papers reported that treatment with nicotinic acid is effective. We have established an animal model to elucidate the mechanism of toxicity of the poisonous mushroom Clitocybe acromelalga. Diet containing Clitocybe acromelalga was fed to niacin-deficient rats for 24 hours (designated as day 0). The food intake decreased to about one-half compared with that of day before, and body weight loss was noted. Although the diet was returned to the control diet on day 1, the food intake did not recover until day 7, and body weight gain was not seen until day 6. A severe symptom resembling acromelalgia in humans started to appear on day 3. This is the first report of an animal model for the intoxication of Clitocybe acromelalga in humans. Since no similar symptom resembling human intoxication was seen in a previous rodent study, the niacin-free/tryptophan-limited diet used in the present study may have contributed to the result.