Sparing effects of intrauterine treatment with prostaglandin E2 on luteal function in cycling gilts

Summary. Luteal cells were obtained by digestion of luteal tissue of cyclic (day 12) and early pregnant (days 12, 20 and 30) pigs. Suspensions of the dispersed luteal cells (5 x 104 cells ml \m=-\1) were incubated for 2 h in minimum essential medium (MEM) alone (control) and MEM with different concentrations of prostaglandin FF2\ g=a\(PGF2\g=a\) and PGE2 (0\m=.\01,0\m=.\1,1, 10, 100 and 1000 ng ml \m=-\1) and luteinizing hormone (LH) 100 and 1000 ng ml\m=-\1, or with combinations of LH+ PGF2\g=a\and LH + PGE2. Net progesterone production was measured in the incubation media by direct radioimmunoassay.The overall response pattern of the luteal cells to exogenous hormones on day 12 of the oestrous cycle and pregnancy differed (P < 0\m=.\5) from treatment on day 20 and 30 of pregnancy. In general progesterone production was higher (P < 0\m=.\5) and the response to PGF2\g=a\ and PGE2 treatment was most obvious on day 12 of the oestrous cycle and pregnancy. Overall, PGF2\g=a\ stimulated progesterone production in a dosedependent manner (P < 0\m=.\05). The response to PGE2 was of a quadratic nature (P < 0\m=.\05) in which the lowest and the highest doses of PGE2 were associated with a greater production of progesterone than were the intermediate doses. Treatment of luteal cells with PGF2\g=a\ + LH or PGE2 + LH caused overall inhibition (P < 0\m=.\05) of progesterone production compared with treatment with each hormone alone. This interaction was not affected by the dose of LH used.These findings indicate that PGF2\g=a\ and PGE2 are involved in the autocrine control of corpus luteum function.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of prostaglandins on luteal function during early pregnancy in pigs

Więsak

Hunter²,

Foxcroft³

1992

“…In the control group, each horn received intrauterine vehicle (5 mL of 1% v/v ethanol saline) infusions. In the experimental group, doses of hormones used were similar to those previously published (Ford et al 1982, Akinlosotu et al 1986). Randomly selected horns within each gilt received hormonal infusions: E 2 (833 ng or 33.3 µg per infusion), PGE2 (200 µg per infusion), or E 2 (833 ng or 33.3 µg per infusion) simultaneously with PGE2 (200 µg per infusion) whereas the contralateral horn received only vehicle infusions.…”

Section: Incubation Of Endometrial Explants In Vitro With E2mentioning

confidence: 93%

Prostaglandin F2α promotes angiogenesis and embryo–maternal interactions during implantation

Kaczyński¹,

Kowalewski²,

Wacławik³

2016

“…I.u. infusion of PGE 2 delays the decline in plasma progesterone concentrations that normally occurs around day 15 and extends the luteal function in cyclic gilts (Akinlosotu et al 1986). Greater PGE 2 secretion in the gravid uterine horn of unilaterally pregnant pigs is associated with increased luteal weights and progesterone concentrations of ipsilateral CLs (Christenson et al 1994).…”

Section: Role Of Pgs During Pregnancy Establishmentmentioning

confidence: 95%

Novel insights into the mechanisms of pregnancy establishment: regulation of prostaglandin synthesis and signaling in the pig

Wacławik

2011

Ovarian progesterone induces essential changes leading to a temporary state of uterine receptivity for conceptus implantation. Estrogens secreted by the porcine conceptus on days 11 and 12 of pregnancy provide the initial signal for maternal recognition of pregnancy and maintenance of a functional corpus luteum (CL) for continued production of progesterone. As prostaglandins F 2a (PGF 2a ) and E 2 (PGE 2 ) exert opposing actions on the CL, a tight control over their synthesis and secretion is critical either for the initiation of luteolysis or maintenance of pregnancy. One of the supportive mechanisms by which conceptus inhibits luteolysis is changing PG synthesis in favor of luteoprotective PGE 2 . Conceptus PGE 2 could be amplified by PGE 2 feedback loop in the endometrium. In pigs, as in other species, implantation and establishment of pregnancy is associated with upregulation of expression of proinflammatory factors, which include cytokines, growth factors, and lipid mediators. The conceptus produces inflammatory mediators: interferon g and interferon d, interleukins IL1B and IL6, and PGs, which probably activate inflammatory pathways in the endometrium. The endometrium responds to these embryonic signals by enhancing further progesterone-induced uterine receptivity. Understanding the mechanisms of pregnancy establishment is required for translational research to increase reproductive efficiencies and fertility in humans and animals.