Plasma luteinizing hormone during pregnancy in the pig

Ziȩcik, Adam J.; Tilton, J. E.; Weigl, R.M.; Williams, Gary L.

doi:10.1016/0378-4320(83)90029-5

Cited by 25 publications

(18 citation statements)

References 14 publications

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“…The levels of LH in early and mid-pregnancy are similar to those observed in the mid-luteal phase of the oestrous cycle (Ziecik et al, 1982(Ziecik et al, /1983 (Parvizi etal, 1976;Kraeling etal, 1992). In miniature pigs, ovariectomy during the follicular phase, and ovariectomy on day 100 of pregnancy followed by abortion, result in a similar increase in LH secretion (Parvizi et al, 1976).…”

Section: Introductionsupporting

confidence: 51%

“…The concentrations of plasma LH fluctuate in an episodic and pulsatile manner throughout pregnancy (Ziecik et al, 1982(Ziecik et al, / 1983Kraeling et al, 1992). The levels of LH in early and mid-pregnancy are similar to those observed in the mid-luteal phase of the oestrous cycle (Ziecik et al, 1982(Ziecik et al, /1983 (Parvizi etal, 1976;Kraeling etal, 1992).…”

Section: Introductionmentioning

confidence: 90%

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Endocrine bases of lactational anoestrus in the sow

Quesnel¹,

Prunier²

1995

Reprod. Nutr. Dev.

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Summary ― Parturition in the sow is followed by a period of anovulation which is prolonged by lactation. Follicular development and luteinizing hormone (LH) secretion are depressed during the last month of pregnancy. After parturition, LH secretion increases but is again inhibited by the establishment of lactation. Lactating sows are submitted to stimuli originating from the young, whose intensity culminates 3-14 d post-partum (pp), and to high nutrient requirements for milk production. The

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Section: Introductionsupporting

confidence: 51%

Section: Introductionmentioning

confidence: 90%

Endocrine bases of lactational anoestrus in the sow

Quesnel¹,

Prunier²

1995

Reprod. Nutr. Dev.

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“…Furthermore, the amount of LH released at each pulse was reduced of about 50% by ACTH treatment during the 2 nd and 3 rd trimester. In the pig, LH is the main luteotropic factor from early to mid-gestation [23,45,46]. The lowfrequent pulsatile LH release found in our study and previously [23] seems to be crucial for proper function of porcine corpora lutea, which are the main source of progesterone and necessary for maintaining pregnancy [5,47].…”

Section: Discussionmentioning

confidence: 58%

“…In pregnant pigs, the concentration of maternal LH is low and with minor pulsatile secretion [23][24][25][26]. But all in all, only little information is available on gonadotropin concentration during porcine pregnancy and during stressful conditions of pregnancy.…”

mentioning

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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“…In the sow, the plasma level of LH in early and mid-pregnancy is comparable to its concentration in the mid-luteal phase of the oestrous cycle (4-5 ng/ml), but the LH pulses occurring in the second half of pregnancy are less numerous and of a lower amplitude (Ziecik, Tilton, Weigh & Williams, 1982. In the ewe, the LH concentrations in the blood during early pregnancy are low (Niswender, Roche, Foster & Midgley, 1968).…”

Section: Sowmentioning

confidence: 90%