Local transfer of prostaglandin E₂ into the ovary and its retrograde transfer into the uterus in early pregnant sows

Abstract

This study was designed to establish (a) whether prostaglandin E 2 (PGE 2 ) can reach the ovary and oviduct by a local pathway and what is the contribution of lymphatic vessels to this transfer, and (b) whether PGE 2 can permeate from venous and lymphatic vessels of the mesometrium to arterial blood and be delivered to the uterine horn during maternal recognition of pregnancy in gilts. The reproductive tract was excised from gilts (n = 10) on day 14 after mating. The uterine horn was isolated with the ovary and broad ligament and perfused with warmed and oxygenated autologous blood. A total dose of 5.5 × 10 7 disintegrations per min (d.p.m.) (49 ng) [ 3 H]PGE 2 was infused into the small branches of the uterine vein on the broad ligament or into the lymphatic vessels. Frequent blood samples were collected from the branch of the uterine artery and from the venous effluent. Tissue samples were collected from the uterine horn, the ovary and the broad ligament. The concentration of [ 3 H]PGE 2 was significantly higher in the ovary (P < 0.001), oviduct (P < 0.01), endometrium (P < 0.01), myometrium (P < 0.001) and mesometrium (P < 0.001) after infusion of [ 3 H]PGE 2 into lymphatic vessels than into the branches of the uterine vein. In contrast, the concentration of [ 3 H]PGE 2 was significantly higher in arterial blood supplying the uterine horn (P < 0.01) and in the venous effluent (P < 0.001) after infusion of [ 3 H]PGE 2 into the branches of the uterine vein than into lymphatic vessels. These results demonstrated local transfer of [ 3 H]PGE 2 into the ovary, oviduct and uterine horn from lymphatic and venous vessels of the mesometrium. However, the efficiency of this transfer was considerably higher after infusion into lymphatic vessels than into branches of the ovarian vein. We conclude that the lymphatic pathway is a fundamental mechanism in the local transfer of PGE 2 from the uterus to the ovary and oviduct during early pregnancy in the pig.

Local and Systemic Effects of Embryos on Uterine Tissues During Early Pregnancy in Pigs

“…We suggest that PGE2 may also be produced by the endometrium from isolated part of the uterus and next be transported within the mesometrial blood and lymph vessels from one part of the uterus to another independently of the presence of embryos in the uterus. Our results confirmed the concept of local regulation of PGE2 secretion and its retrograde transfer into the uterus in pigs [32,48]. We demonstrated that isolation of one uterine horn both during days 12-14 of early pregnancy and the estrous cycle may enhance the mechanism of luteotrophic PGE2 production in the isolated part of the uterine horn.…”

Contractile effect of PGF2α and PGE2 on isolated branches of uterine and ovarian artery in different days of estrous cycle and early pregnancy in pigs

“…A similar effect occurs in lymphatic-arterial communications, as revealed in the ewe (Heap et al 1985(Heap et al , 1989 and sow (Krzymowski et al 1986, Stefańczyk--Krzymowska et al 2005, Chłopek et al 2008). Celia and Osol (2002) demonstrated that phenylephrine and acetylcholine infused into isolated rat uterine vein are able to alter the tone of adjacent uterine arteries in a concentration-dependent manner.…”

“…The local destination transfer of this PG to the ovary was, in early pregnancy, significantly reduced in comparison to the luteolysis period (Stefańczyk-Krzymowska et al 1990). However, transfer of PGE 2 to the ovary was intensified during the luteal phase of the estrous cycle and in early pregnancy and reduced in the luteolysis period (Stefańczyk-Krzymowska et al 2005, Chłopek et al 2008. This different distribution of PGs in reproductive organs may in turn change the function of blood vessels.…”

“…In pigs, PGF 2 α permeates in broad ligament vasculature from venous Stefańczyk-Krzymowska et al 1990). Our recent studies demonstrated the retrograde transfer of PGE 2 from the uterine lymph and venous blood to arterial blood supplying the uterine horn and its local destination transfer to arterial blood supplying the ovary in early pregnant (Stefańczyk-Krzymowska et al 2005 as well as in cycling gilts (Chłopek et al 2008).…”

Differential Gene Expression in Ovaries of Pregnant Pigs with High and Low Prolificacy Levels and Identification of Candidate Genes for Litter Size

“…During pregnancy, an increased blood flow between uterus and ovary has been detected [29,30], as well as a segregation of progesterone by the corpus luteum to maintain the lining of the endometrium in early pregnancy. Other studies in pigs [31] have also shown that ovarian hormones influence retrograde transfer of prostaglandin E 2 secreted by the conceptus. Despite this previous evidence, the majority of expression studies in porcine reproductive tissues have been carried out mainly in preimplantation uterus [2].…”