Ovarian Response to Pregnant Mare Serum Gonadotropin and Porcine Pituitary Extract in Gilts Actively Immunized against Gonadotropin Releasing Hormone

Context It is a common problem that replacement gilts exhibit delayed oestrus and non-oestrus in pig production. Aims This study explored the use of progesterone and pregnant mare serum gonadotropin (PMSG) to promote oestrus and to restore the reproductive capacity of sows. Methods A total of 90 long-term non-oestrus replacement gilts were randomly divided into three groups. Group A consisted of 30 sows that were normally fed for 20 days, followed by injections of 1000 IU of PMSG on the morning of the 21st day and 100 μg of gonadotropin-releasing hormone on the 24th day. Group B consisted of 30 sows that were continuously fed with altrenogest (20 mg/head.day) for 18 days, followed by injections of 1000 IU of PMSG on the morning of the 21st day and 100 μg of gonadotropin-releasing hormone on the 24th day. Group C (control group) consisted of 30 sows that were normally fed for 20 days, followed by injections of 3 mL of physiological saline on the morning of the 21st day and 3 mL of saline on the 24th day. Oestrus identification was performed in all three groups, and sows underwent artificial insemination after the injection of gonadotropin-releasing hormone or saline. Key results We found that the follicles of long-term non-oestrus replacement gilts were not developed, and follicle diameters were <4 mm. The oestrus rate and pregnancy rate of the sows in Group B were significantly lower than those in Group A (30% vs 66.7% and 66.7% vs 90%) respectively. There was no difference in the litter size between Group A and Group B (11.2 vs 11.5). The sows in Group C exhibited no oestrus and no pregnancy. After treatment with progesterone and PMSG, the follicle diameters of sows in oestrus were significantly greater than those of sows in non-oestrus, and the levels of oestradiol, luteinising hormone and follicle-stimulating hormone were significantly higher than those of sows in non-oestrus. Conclusions This study showed that progesterone and PMSG treatment can alter the reproductive hormone levels and follicle diameters in long-term non-oestrus replacement gilts, promote oestrus and restore reproductive capacity in sows. Implications This study provides a method for the use of hormone-treated gilts to maximise the reproductive potential of gilts.

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Developmental changes in the gonadotropin releasing hormone neuron of the female rabbit: effects of tamoxifen citrate and pregnant mare serum gonadotropin

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y93-114 ◽

1993 ◽

Vol 71 (10-11) ◽

pp. 761-767 ◽

Cited By ~ 3

Author(s):

Warren G. Foster ◽

John F. Jarrell ◽

Edward V. YoungLai

Keyword(s):

Gonadotropin Releasing Hormone ◽

Developmental Changes ◽

Tamoxifen Treatment ◽

Control Group ◽

Releasing Hormone ◽

Pregnant Mare Serum Gonadotropin ◽

Age Related ◽

Developmental Shift ◽

Tamoxifen Citrate ◽

Serum Gonadotropin

Developmental changes in immunostained gonadotropin releasing hormone neurons were demonstrated in female rabbits assigned to the following treatment groups: (i) tamoxifen citrate, 10 mg∙kg−1∙day−1, in sesame seed oil (vehicle) (n = 24) or (ii) vehicle alone (control, n = 24) for 108 days; and (iii) 50 IU of pregnant mare serum gonadotropin on postnatal days 22 and 25 (n = 24) or vehicle on nontreatment days. Treatments had no effect on the total number of immunostained cells, but there was a significant (p = 0.0160) developmental shift from cells with smooth processes to rough. Group comparisons revealed that there was a significant (p < 0.001) age-related increase in the number of rough cells in pregnant mare serum treated rabbits between days 25 and 75, indicating an advancement in the shift from smooth to rough cells. Plasma gonadotropin levels, ovarian follicular development, and the developmental shift from smooth to rough cells were markedly suppressed by tamoxifen treatment compared with rabbits of the control group, while no difference in estradiol levels were found. Our results suggest that a developmental shift in gonadotropin releasing hormone cell morphology from smooth to rough precedes sexual maturity in the female rabbit.Key words: development, sexual maturation, gonadotropin releasing hormone, puberty, immunohistochemistry.

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Endocrine and molecular milieus of ovarian follicles are diversely affected by human chorionic gonadotropin and gonadotropin-releasing hormone in prepubertal and mature gilts

Scientific Reports ◽

10.1038/s41598-021-91434-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Adam J. Ziecik ◽

Jan Klos ◽

Katarzyna Gromadzka-Hliwa ◽

Mariola A. Dietrich ◽

Mariola Slowinska ◽

...

Keyword(s):

Chorionic Gonadotropin ◽

Human Chorionic Gonadotropin ◽

Hormone Receptors ◽

Cell Function ◽

Ovarian Follicle ◽

Molecular Transport ◽

Gonadotropin Releasing Hormone ◽

Matrix Remodeling ◽

Releasing Hormone ◽

Serum Gonadotropin

AbstractDifferent strategies are used to meet optimal reproductive performance or manage reproductive health. Although exogenous human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone (GnRH) agonists (A) are commonly used to trigger ovulation in estrous cycle synchronization, little is known about their effect on the ovarian follicle. Here, we explored whether hCG- and GnRH-A-induced native luteinizing hormone (LH) can affect the endocrine and molecular milieus of ovarian preovulatory follicles in pigs at different stages of sexual development. We collected ovaries 30 h after hCG/GnRH-A administration from altrenogest and pregnant mare serum gonadotropin (eCG)-primed prepubertal and sexually mature gilts. Several endocrine and molecular alternations were indicated, including broad hormonal trigger-induced changes in follicular fluid steroid hormones and prostaglandin levels. However, sexual maturity affected only estradiol levels. Trigger- and/or maturity-dependent changes in the abundance of hormone receptors (FSHR and LHCGR) and proteins associated with lipid metabolism and steroidogenesis (e.g., STAR, HSD3B1, and CYP11A1), prostaglandin synthesis (PTGS2 and PTGFS), extracellular matrix remodeling (MMP1 and TIMP1), protein folding (HSPs), molecular transport (TF), and cell function and survival (e.g., VIM) were observed. These data revealed different endocrine properties of exogenous and endogenous gonadotropins, with a potent progestational/androgenic role of hCG and estrogenic/pro-developmental function of LH.

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