The pathogenesis of methylhydrazine sulfate induced distal tail gangrene.

Finely divided methylhydrazine sulfate was fed to 42 rats at a concentration of 300 mg per kg of ground commercial diet. After 42 days most of the rats developed hyperkeratosis and edema of the terminal 2-6 cm of the tail. Twenty-five rats fed longer than 98 days all developed tail tip gangrene varying in length from 0.4 to 2.5 cm. Since 24 control rats which were fed the ground commercial diet grew satisfactorily and did not develop any alterations in the skin of the tail, the tail tip gangrene is ascribed to the presence of MHS in the diet. In view of the presence of epidermal hyperplasia and edema in every instance, and the occurrence of acute folliculitis in a majority of test rats, the tail tip gangrene is believed to be due to epithelial alterations rather than an injury of the blood vessels. This experimental model may prove useful for epidermal studies, because MHS fed rats are active and energetic. Secondly, the MHS skin changes apparently can be produced more rapidly than with diets deficient in unsaturated fatty acids.