[Results of histochemical and biochemical studies of uterus of gilts during the estrous cycle].

Alkaline phosphatase activity as well as lipid, polysaccharide, glycogen, and acid mucopolysaccharide levels in the uteri of 79 gilts were histochemically tested during the first three sexual cycles. Intra-cyclic alkaline phosphatase activity exhibited clearly pronounced variations in the surface epithelium, with maximum values reached in metoestrus, and moderate variations in the endometrial stroma, with maximum values reached in dioestrus. Cycle-dependent variations were recordable also from the glycogen and lipid levels in the surface and glandular epithelia and from the acid mucopolysaccharide levels in the endometrial stroma. The activity of alkaline phosphatase as well as the levels of glycogen and acid mucopolysaccharides during the first cycle still were lower than those in the second and third. Biochemical examinations of the endometrium revealed significant cycle-dependent variations in the activities of alkaline phosphatase, inorganic pyrophosphatase, and succinate-dehydrogenase as well as in the concentrations of soluble protein and glycogen, with maximum values being recordable on the tenth day of cycle. No significant intracyclic variations were recordable from the activities of acid phosphatase as well as of aspartate alanine-amino transferase.