Medycyna Wet. 64 (4b), 511-514, 2008
Stefańczyk-Krzymowska S., Krzymowski T.
Local destination and retrograde transfer of uterine prostaglandins F2a and E2 and their role in the regulation of the estrous cycle
A new stage in the knowledge of the role of blood and lymphatic vessels of the broad ligament in the regulation of the estrous cycle is presented. Contrary to common opinion, recent studies have shown that the destination transfer of prostaglandins F2a and E2 from the uterus to the ovary, as a result of the local morphological adaptation of mesometrial and mesovarian vasculature, is realized principally by lymph and lymphatic vessels of the broad ligament. The retrograde transfer of both prostaglandins from uterine lymph and venous blood to the uterine arterial blood take place in mesometrium. During the luteal phase of the estrous cycle retrograde transferred PGF2a together with progesterone delivered with blood constricts the mesometrial artery and considerably reduces the uterine blood supply. This temporary local ischemia initiates cyclic reconstruction of the endometrium and changes its secretary function. Retrograde transfer of PGE2 together with estradiol and embryo signals dilates of the mesometrial arterial vessels and increases uterine blood supply. Moreover, retrograde transfer of PGF2a prevents cyclic and early pregnant corpus luteum against luteolysis. This mechanism is especially important in the regulation of the early pregnancy.
Keywords: reproduction, estrous cycle, prostaglandins, retrograde transfer, destination transfer