EN
The aim of the present study was to establish: a) whether PGE₂ can permeate from venous and lymphatic vessels of the mesometrium to arterial blood and be retrograde transferred to the uterine horn during the porcine oestrous cycle; and b) whether PGE₂ can reach the ovary and oviduct by local destination transfer. The experiments were performed on days 9-10 (middle luteal phase), 13-14 (initiation of luteolysis), 16-18 (follicular phase) of the oestrous cycle. [³H]PGE₂ at a total dose of 5.5 × 10⁷ d.p.m. (49 ng) was infused into the most superficial layer of the myometrium under the serosa. The results demonstrated the permeation of PGE₂ from venous blood, uterine lymph and mesometrial tissues into arterial blood and its retrograde transfer into the uterine horn. The efficiency of retrograde transfer of prostaglandin to the uterine horn was high in all phases of the oestrous cycle, excluding the period of luteolysis. The local destination transfer of PGE₂ from the uterus to the ovary and oviduct was also demonstrated. The efficiency of local destination transfer of PGE₂ to the ovary was the highest in the middle luteal phase. The authors conclude that retrograde and local destination transfer of PGE₂ may enable effective access of this hormone to target organs and reduce its outflow with venous blood.