Differential patterns in luteal prolactin and LH receptors during pregnancy in sows and ewes

H, Jammes; Schirar, A.; Djiane, Jean

doi:10.1530/jrf.0.0730027

Cited by 26 publications

(19 citation statements)

References 29 publications

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“…It remains open whether the lacking progesterone increase after ACTH is the result of lower capacity of the adrenals, corpora lutea and/or placenta. However, it has to keep in mind that a complex of l u t e o t r o p i c c o m p o n e n t s ( L H , p r o l a c t i n , endogenous opiods) and its interaction with progesterone is involved in late gestation in the sow [42,[50][51][52].…”

Section: Discussionmentioning

confidence: 99%

Alteration of Reproductive Hormone Levels in Pregnant Sows Induced by Repeated ACTH Application and Its Possible Influence on Pre- and Post-natal Hormone Secretion of Piglets

Brüssow¹,

Schneider²,

Kanitz

et al. 2005

Journal of Reproduction and Development

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Abstract. Prenatal stress has been seen as a reason for reproductive failures in pig offspring mostly originated or mediated by changed maternal functions. Experiments were conducted in pregnant gilts (n=32) to characterize effects of elevated maternal glucocorticoids on the secretion of reproductive hormones (LH, progesterone) during the 1 st (EXP 1), 2 nd (EXP 2) and 3 rd (EXP 3) trimester of pregnancy (TP). Transiently elevated cortisol release was repeatedly achieved by application of 100 IU adenocorticotropic hormone (ACTH) (Synacthen Depot®) six times every second day beginning either on day 28 (EXP 1), day 49 (EXP 2) or day 75 of pregnancy (EXP 3). Glucocorticoid concentrations were examined in umbilical blood vessels of fetuses which mothers were subjected to ACTH at 2 nd and 3 rd TP (EXP 4). Furthermore, the pituitary function of newborn piglets of EXP 2 was checked by a LH-RH challenge test. In sows, LH concentrations were at low basal level (0.1-0.2 ng/ ml) but with pulsatory release pattern during each TP. The number of LH pulses/6 h (LSM ± SE) of saline treated Controls increased with ongoing pregnancy and decreased to the 3 rd TP (1.3 ± 0.2 in EXP 1 vs. 2.0 ± 0.1 in EXP 2 vs. 1.4 ± 0.1 in EXP 3, p<0.05). After ACTH treatment the number of LH pulses left unchanged in Experiments 1 and 2 (1.3 ± 0.2 and 1.5 ± 0.1) and decreased in EXP 3 (0.8 ± 0.2, p<0.05). Differences (p<0.05) were obtained comparing the LH pulse number of ACTH and saline treated sows at the 2 nd and 3 rd TP. Moreover, areas under the curve (AUC) of each LH pulse and of LH over baseline were significantly reduced by treatment. Levels of progesterone increased (p<0.05) for 150 to 170 min after each ACTH application both in EXP 1 and EXP 2, but not in EXP 3. The mean progesterone concentration was different between trimesters, and ACTH and Controls (1 st TP: 30.0 ± 0.9 and 24.4 ± 0.7 ng/ml; 2 nd TP: 35.5 ± 0.9 and 29.1 ± 1.0 ng/ml; 3 rd TP: 13.6 ± 0.2 and 13.1 ± 0.1 ng/ml; p<0.05). In fetuses (n=87) recovered 3 h after ACTH or saline (EXP 4), the plasma cortisol concentrations were significantly increased in umbilical vein (93.7 ± 5.5 vs. 47.0 ± 5.3 nmol/l) and artery (95.7 ± 5.4 vs. 66.4 ± 5.4 nmol/l), and in periphery (46.8 ± 5.3 vs. 27.1 ± 5.3 nmol/l) compared to controls. Plasma ACTH concentrations, however, did not differ in fetuses of both treatment groups. Postnatal LH-RH challenge tests (1 st and 28 th day post partum) induced LH surges in female piglets (n=67) both of ACTH and saline treated sows, but did not differ between groups (1 st day: 7.2 ± 0.8 vs. 8.1 ± 0.7 ng/ml; 28 th day: 10.5 ± 1.7 vs. 13.6 ± 2.2 ng/ml). However, basal LH of piglets whose mothers were submitted to ACTH during 2 nd TP was lower on 1 st day (1.7 ± 0.2 vs. 2.3 ± 0.2 ng/ml, p<0.05) but not on 28 th day (1.0 ± 0.2 vs. 1.1 ± 0.2 ng/ml). However in both groups, the basal LH was always higher on 1 st as on 28 th day (p<0.05). Thus, chronic intermittent ACTH administration is able to influence the release pattern of maternal reproductive hormones. However, ...

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Section: Discussionmentioning

confidence: 99%

Alteration of Reproductive Hormone Levels in Pregnant Sows Induced by Repeated ACTH Application and Its Possible Influence on Pre- and Post-natal Hormone Secretion of Piglets

Brüssow¹,

Schneider²,

Kanitz

et al. 2005

Journal of Reproduction and Development

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“…The number of PRL receptors in porcine CL is low during the early part of pregnancy but increases significantly in middle and late pregnancy [14]. Correspondingly, plasma P 4 concentrations also increase dramatically at a similar period [14], indicating a luteotropic effect of PRL.…”

Section: Discussionmentioning

confidence: 91%

“…PRL has important effects in regulating luteal function, especially in the rat [8], where PRL increases luteal LH receptors [9] as well as in vivo and in vitro production of P 4 [10,11]. PRL receptors have been found in CL of several species, i.e., the hamster, rat, pig, and ewe [12][13][14]; but PRL binding sites have not been studied in the pregnant hamster. The number of PRL receptors in the hamster may also be different between Days 4 and 12 of pregnancy.…”

Section: Introductionmentioning

confidence: 99%

Follicle-Stimulating Hormone, Human Chorionic Gonadotropin, and Prolactin Receptors in Hamster Corpora Lutea or Dispersed Luteal Cells during Pregnancy1

Yuan

Wang

Greenwald

1995

Biology of Reproduction

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In vitro progesterone (P4) production by hamster luteal cells is stimulated throughout pregnancy by FSH and LH. Prolactin (PRL) by itself, however, increases P4 synthesis only on Day 12; on Day 4, FSH+LH+PRL induces optimal P4 secretion [Biol Reprod 1994; 51:43-49]. In light of these findings, in this study we investigated FSH, hCG, and PRL receptors in hamster CL or dispersed luteal cells on Days 4, 8, and 12 of pregnancy. Scatchard analysis of hamster CL on Days 4 and 8 showed considerably more unoccupied hCG receptors than FSH receptors: on Day 4, there was 9.5 fmol/mg protein for FSH binding sites vs. 1741 fmol/mg protein for hCG binding. Moreover, the binding affinity of hCG was greater than for FSH: the Day 4 Kd was 0.136 nM for hCG vs. 0.308 for FSH. Similar differences were observed on Day 8. Dispersed luteal cells (large+small cells) were incubated for 24 h with or without 10 ng of ovine FSH, LH, and PRL or human recombinant FSH (r-hFSH), alone or in different combinations. The cells were then washed and incubated for 4 h with iodinated hCG, FSH, or PRL with or without 100-fold excess of unlabeled hormones. The number of binding sites per 200,000 luteal cells did not change appreciably for FSH and hCG on Days 4 and 12 of pregnancy, whereas PRL binding sites significantly increased on Day 12.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…It is well known that P 4 levels during the early-mid luteal phase increase rapidly from day 4 to day 10 after estrus in ewes [9] . Pregnancy maintenance is largely dependent on P 4 of luteal source for approximately the first 50 days of gestation [10] . Therefore, it would be advantageous to note that high plasma P 4 concentrations during the luteal phase are important for maintaining pregnancy [11] .…”

Section: Introductionmentioning

confidence: 99%

The Effect of Post-Mating Progesterone Supplement on Pregnancy and Lambing Rates of Ewes Bred Out-of-season

Husein¹,

Ababneh²,

Hijazi³

2007

American J. of Animal and Veterinary Sciences

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Abstract:The objective of this experiment was to determine whether post-mating progesterone (P 4 ) supplement improves pregnancy and lambing rates in ewes bred during the seasonal anestrous period. In June, 39 synchronized to estrus Awassi ewes were allowed with four harnessed fertile rams immediately following CIDR-G device removal (day 0 and 0 hour). Five days following ram introduction, ewes were randomly assigned to four groups to be treated post-mating with intramuscular injections of 20 mg P 4 supplement once daily from day 5 to day 9 (P 4 -D5-9), days 10 to 14 (P 4 -D10-14), days 5 to 14 (P 4 -D5-14) or did not receive P 4 supplement (control). Blood samples were collected from all ewes for P 4 analysis. Progesterone concentrations prior to CIDR-G insertion were basal and no differences in P 4 concentrations were found on days -12, -10 and between days 0 and 5 among groups. Progesterone concentrations between days 5 and 15 differed (p<0.001) significantly due to treatment effect. Maximum P 4 concentrations were reached on day 9 in group P 4 -D5-9 and between days 11 and 15 in groups P 4 -D10-14, P 4 -D5-14, and control. Pregnancy was diagnosed based on day 19 P 4 levels and day 30 ultrasonic examination in 5/10, 6/10, 5/10, and 5/9 ewes in groups P 4 -D5-9, P 4 -D10-14, P 4 -D5-14 and control, respectively. Pregnancy loss was detected by ultrasonography on day 45 in 3/6 and 3/5 ewes in P 4 -D10-14, P 4 -D5-14 groups only. Overall pregnancy (53.8%) and lambing (41%) rates were similar among groups and were not influenced by P 4 supplement. In conclusion, P 4 supplement administered intramuscularly between days 5 and 14 post-mating is not effective in improving pregnancy, embryonic survival and lambing rates in Awassi ewes pretreated out-of-season. Pregnancy loss which occurred only in P 4 -D10-14 and P 4 -D5-14 groups maybe attributed to factors including the sharp decrease in P 4 concentrations on day 15 and stress experienced during the period of maternal recognition of pregnancy process.

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Differential patterns in luteal prolactin and LH receptors during pregnancy in sows and ewes

Abstract: In the ewe, the receptor content of LH and prolactin did not change very much during pregnancy. The corpus luteum showed normal luteal function until parturition although it was not necessary for maintenance of pregnancy in the ewes.

Cited by 26 publications

References 29 publications

Alteration of Reproductive Hormone Levels in Pregnant Sows Induced by Repeated ACTH Application and Its Possible Influence on Pre- and Post-natal Hormone Secretion of Piglets

Alteration of Reproductive Hormone Levels in Pregnant Sows Induced by Repeated ACTH Application and Its Possible Influence on Pre- and Post-natal Hormone Secretion of Piglets

Follicle-Stimulating Hormone, Human Chorionic Gonadotropin, and Prolactin Receptors in Hamster Corpora Lutea or Dispersed Luteal Cells during Pregnancy1

The Effect of Post-Mating Progesterone Supplement on Pregnancy and Lambing Rates of Ewes Bred Out-of-season

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