[Comparative histoenzymological demonstration of certain digestive enzymes in the intestinal epithelium of the mouse and the chicken during a 24-h-period (author's transl)].

At different times of the day activities of hydrolytic (alkaline and acid phosphatase, esterase) and oxydative (succinodehydrogenase, cytochromoxidase, monoaminoxidase) enzymes were studied in the epithelium of the upper part of the jejunum in the adult female mouse and the adult laying chicken. In both species the activities of the intestinal enzymes showed marked circadian variations with respect to their activity and distribution pattern. The variations did not principally differ in both species. The species' differences were mainly expressed by phase shifts of about 12 h in the occurrence of maximal and minimal activities according to the different phases of the locomotor activity of the mainly night-active mice and day-active chickens.