FOOD-DEPRIVATION INCREASES APOPTOTIC CELL COUNTS INDUCED BY 1,2-DIMETHYLHYDRAZINE IN RAT DESCENDING COLONIC AND RECTAL CRYPTS

The frequency of apoptosis after treatment with 1,2-dimethylhydrazine (DMH) was counted in the descending colonic and rectal crypts of food- deprived and fed rats. Food-deprived or fed rats were subcutaneously i njected with DMH (100 mg/kg body weight). Six hours after the injectio n, apoptotic cells were observed in crypt regions by light microscopy. The incidence of DMH-induced apoptosis in food-deprived rats was sign ificantly higher than in fed rats. The incidence appeared to be higher in descending colon than in rectum. PAS staining revealed that DMH tr eatment lowered mucin secretion in crypts, which was substantially low ered by food deprivation. The effect of food deprivation on apoptosis induced by DMH may be due to the decrease in mucus barrier against DMH .