Effects of Luteinizing Hormone (LH), PGE2, 8-Epi-PGE1, 8-Epi-PGF2α, Trichosanthin and Pregnancy Specific Protein B (PSPB) on Secretion of Prostaglandin (PG) E (PGE) or F2α (PGF2α) In Vitro by Corpora Lutea (CL) From Nonpregnant and Pregnant Cows

Weems, Y.S.; Lammoglia-Villagómez, Miguel Ángel; Ávila, Héctor Raymundo Vera; Randel, R. D.; Sasser, R.G.; Weems, C.W.

doi:10.1016/s0090-6980(98)00030-6

Cited by 65 publications

(33 citation statements)

References 34 publications

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“…Pituitary LH and ovarian and/or uterine PGE2 are known to stimulate P4 and PGE2 production and output from the bovine CL [1,10,11,25]. Both luteotropic factors (aPGF2α), dinoprost with an 11-day interval; (c) synchronized using two injections of aPGF2α, cloprostenol with an 11-day interval; (d) synchronized using two injections of aPGF2α, luprostiol with an 11-day interval; (e) synchronized using a gestagen implant, norgestomet; and (f) synchronized using norgestomet with additional injection of dinoprost on the day of implant removal.…”

Section: Discusssionmentioning

confidence: 99%

“…Pituitary LH and ovarian and/or uterine PGE2 are known to stimulate P4 and PGE2 production and output from the bovine CL [1,10,11,25]. Both luteotropic factors Fig.…”

Section: Discusssionmentioning

confidence: 99%

“…Arachidonic acid metabolites, such as PGE2 and PGI2, have been proposed to have multiple roles as luteotrophic, luteostatic or luteoprotective signals during the estrous cycle and pregnancy [8][9][10]. In fact, PG may regulate cell proliferation and differentiation and may stimulate P4 production regulating/stimulating CL formation, development and maintenance [7,11,12].In the absence of an embryo in the uterus, the process of CL regression begins on Days 17-19 of the estrous cycle in cows [13]. This process is characterized not only by functional but also structural changes that occur in the luteal steroidogenic and nonsteroidogenic cells [14].…”

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In Vitro Assessment of Progesterone and Prostaglandin E2 Production by the Corpus Luteum in Cattle Following Pharmacological Synchronization of Estrus

Skarzynski

Siemieniuch

Pilawski

et al. 2009

Journal of Reproduction and Development

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Abstract.We studied the secretory function of the corpus luteum (CL) in cows following different estrus synchronization protocols. Estrus was synchronized using one (n=4) or two injections (n=5) of prostaglandin F2α (PGF2α; dinoprost), two injections of different analogues of PGF2α (aPGF2α), luprostiol (n=5) and cloprostenol (n=5), at eleven-day intervals, a gestagen implant (norgestomet, n=5, for 10 days) or norgestomet together with a subsequent dinoprost injection on the day of implant removal (n=5). CL samples were collected by ovariectomy on Day 7-8 of the estrous cycle. Luteal strips were stimulated with LH (100 ng/ml) or prostaglandin E2 (PGE2, 10 -6 M) for 24 h in culture media. The progesterone (P4) and PGE2 concentrations in the media were measured by enzyme immunoassay. In the control CL (spontaneous estrus; n=5), LH and PGE2 stimulated P4 and PGE2 (P<0.001). The effects of both factors on P4 were reduced in the CL following dinoprost-and cloprostenol-synchronized estrus (P<0.05) and were absent in the luprostiol-synchronized CL (P>0.05). In the norgestomet-synchronized CL, the stimulatory effects of LH and PGE2 were higher compared with the CL synchronized by aPGF2α (P<0.05). Pharmacological manipulation of the estrous cycle using aPGF2α may cause lower P4 secretion. Estrus synchronization inhibited CL sensitivity to luteotropic factors. Therefore, attention should be focused on the estrous synchronization method in both in vivo and in vitro studies of CL functions in cattle. Key words: Cattle, Corpus luteum (CL), Estrus synchronization, Progesterone, Prostaglandin E2 (PGE2), Prostaglandin F2α (PGF2α) analogue (J. Reprod. Dev. 55: [170][171][172][173][174][175][176] 2009) he physiological processes of corpus luteum (CL) formation, growth and maintenance might be regulated by many different factors including luteinizing hormone (LH) and prostaglandin (PG)s [1,2]. After ovulation, as the CL forms from the wall of the ruptured follicle, it grows and rapidly vascularizes [3]. The CL is a complex tissue composed of parenchymal (steroidogenic) and nonparenchymal (fibroblast, vascular smooth muscle, pericyte and endothelial) cells [3,4]. Disturbances in physiological conditions and pharmacological manipulations during follicle growth and maturation, ovulation and as well during early CL formation influence the future secretory function of this new formed endocrine gland.The main function of the CL is secretion of progesterone (P4), an important hormone for the establishment and maintenance of a successful pregnancy [1,2,5]. In domestic animals, LH, which is released in a pulsatile fashion from the anterior pituitary, is one of the most potent regulators of P4 production [6]. LH stimulates basal P4 production in small luteal cells via the LH receptor. In addition to pituitary LH, intraluteal substances produced by the component cells of the CL play important roles in regulating P4 production during the luteal stages and pregnancy [1,2,7]. Arachidonic acid metabolites, such as PGE2 and PGI2, have been prop...

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Section: Discusssionmentioning

confidence: 99%

“…Pituitary LH and ovarian and/or uterine PGE2 are known to stimulate P4 and PGE2 production and output from the bovine CL [1,10,11,25]. Both luteotropic factors Fig.…”

Section: Discusssionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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In Vitro Assessment of Progesterone and Prostaglandin E2 Production by the Corpus Luteum in Cattle Following Pharmacological Synchronization of Estrus

Skarzynski

Siemieniuch

Pilawski

et al. 2009

Journal of Reproduction and Development

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“…When administered to cultured bovine luteal cells, PAG-1/PSPB promoted release of the luteotrophic compound, prostaglandin E 2 (PGE 2 ) (Del Vecchio et al, 1995a andWeems et al, 1998a) and an increase in progesterone (Del Vecchio et al, 1996;Weems et al, 1998b). However, other studies reported no increase in progesterone (Del Vecchio et al, 1995a and1995b).…”

Section: Introductionmentioning

confidence: 99%

Autoimmunization of ewes against pregnancy-associated glycoproteins does not interfere with the establishment and maintenance of pregnancy

Egen

Ealy²,

Landon³

et al. 2009

Animal

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Pregnancy-associated glycoproteins (PAGs) are a large grouping of placental proteins that belong to the aspartic peptidase gene family. Although useful to detect pregnancy in ruminant species, the function of these molecules is unclear. Several PAGs expressed by trophoblast binucleate cells can enter the maternal circulation, suggesting that they could have a systemic role in altering maternal physiology. The objective of this work was to examine whether these circulating placental antigens were important in pregnancy by actively immunizing ewes against them. PAGs were purified by pepstatin-affinity chromatography and conjugated to the immunogenic protein, keyhole limpet hemocyanin (KLH). Ewes were immunized with PAG-KLH conjugate (n 5 22) or with KLH alone (n 5 9), and bred to intact rams. Blood samples, collected on Day 0 (day of estrus), Day 10, Days 15 to 25 and weekly throughout pregnancy, were analyzed for PAG by an ELISA. On Day 30, pregnancy was confirmed by ultrasound. Ewes immunized against PAG-KLH produced a range of reactive anti-PAG titers, whereas all immunized ewes had high anti-KLH immunoreactivity. PAGs became detectable in the anti-KLH (control) ewes at Day 21.6 6 2.2 of pregnancy. Those ewes immunized against PAGs (n 5 7), that had very low immunoreactivity toward PAGs, had measurable PAG by Day 22.9 6 1.3, and their PAG serum profiles throughout pregnancy did not differ from the controls. Those exhibiting moderate to high anti-PAG immunoreactivity (n 5 15), had significantly lower PAG concentrations than controls, with antigen not becoming detectable until Day 48.1 6 15.6. The decrease in circulating PAG in the immunized animals did not correlate with changes in pregnancy rates, lamb number or lamb birth weight. These results suggest that while PAGs may play a role in maintaining pregnancy, their major contribution is likely to be at the fetal-maternal interface. Their actions at extra-placental sites are presumably of more secondary importance.

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Tumor necrosis factor-? and its receptor in the corpus luteum of pregnant cows

et al. 2000

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Effects of Luteinizing Hormone (LH), PGE2, 8-Epi-PGE1, 8-Epi-PGF2α, Trichosanthin and Pregnancy Specific Protein B (PSPB) on Secretion of Prostaglandin (PG) E (PGE) or F2α (PGF2α) In Vitro by Corpora Lutea (CL) From Nonpregnant and Pregnant Cows

Cited by 65 publications

References 34 publications

<i>In Vitro</i> Assessment of Progesterone and Prostaglandin E<sub>2</sub> Production by the Corpus Luteum in Cattle Following Pharmacological Synchronization of Estrus

<i>In Vitro</i> Assessment of Progesterone and Prostaglandin E<sub>2</sub> Production by the Corpus Luteum in Cattle Following Pharmacological Synchronization of Estrus

Autoimmunization of ewes against pregnancy-associated glycoproteins does not interfere with the establishment and maintenance of pregnancy

Tumor necrosis factor-? and its receptor in the corpus luteum of pregnant cows

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