Investigations of the course of post-partum period in the merino Polish sheep. IV. Shifts in the intercaruncular regions of uterus (observation in light microscope--LM and in scanning electron microscope--SEM).

Studies on the intercaruncular regions of uterus were carried out on 34 ewes on Days 1-78 of the post-partum period to determine the approximate date of ending post-partum changes and the appearance of morphological sings interrelated with the ovarian cycle phases. It was demonstrated that in sheep the remodelling of endometrium relief lasted until Day 12 of post-partum (p.p.) and at the same time destruction changes in the superficial and glandular epithelium, as well as in the uterine stroma ended. At first, changes in the myometrium (around Day 6--in the longitudinal layer and on Day 10--in the circular layer) were finished. After Day 12 p.p. there was a number of morphological signs indicating the relationship between the ovarian cycle phase and changes in the endometrium of intercaruncular regions of the uterus. At the same time, the role of stromal leucocytes and certain hormones in processes of the involution of uterus was discussed.