Effect of vaccination against GnRH (Bopriva®) in the male pubertal calf

The objective of this experiment was to investigate the effectiveness of a newly developed bovine anti-GnRH vaccine (Bopriva?, Pfizer Animal Health, Australia). A total of 12 peripubertal bull calves aged between 6 and 8 months were used, 2 randomly selected animals served as controls. Animals were vaccinated twice at an interval of 4 weeks with 1ml of Bopriva? (400 μg GnRH-protein-conjugate) subcutaneously in the neck and observed for a total of 36 weeks. Scrotal circumference was measured every week and blood samples were also taken weekly for the determination of testosterone and GnRH antibodies. Three months after the second injection (booster), 5 animals were slaughtered and their testes histologically examined. GnRH antibody titers rapidly began to rise after the second vaccination and reached peak values 3 weeks later. Testosterone concentrations decreased to values below 0.5 ng/ml serum 1 week after the booster and remained at this low level for at least 10 weeks. The following increase of testosterone occurred individually within 11 and 23 weeks after the booster injection. Histological examination of testes in vaccinated animals showed an incomplete spermatogenesis with impaired or no production of spermatids and a reduced diameter of seminiferous tubules. From our results we conclude that in the peripubertal bull two injections with the new bovine anti-GnRH vaccine 4 weeks apart is effective in suppressing testicular growth and testosterone secretion during at least 10 weeks after the booster injection.     

GnRH免疫去势研究进展

促性腺激素释放激素 (GnRH)是由丘脑下部产生并贮存于该腺体内 ,当机体受到一定的刺激时通过血液循环到达靶组织 ,调节丘脑 垂体 性腺轴 ,影响生殖内分泌和生殖细胞的发育。随着生物学、免疫学以及生殖内分泌等多学科的发展 ,出现了一个新的边缘性学科———激素免疫学 ,并由此出现了激素免疫技术 ,即外源的激素作用于机体使机体产生抗体并利用抗体中和机体的内源性激素使其失去生物活性 ,进而使丘脑 垂体 性腺轴的正常生理活动受破坏。文章对GnRH免疫去势在生产中的可行性、作用机制、影响因素、免疫制剂研究及其存在问题等作了综述     

GnRH的调控机制

ＧｎＲＨ由丘脑下部合成［１］,并以脉冲方式分泌进入丘脑下部垂体门脉血系统,到达垂体前叶发挥诱导促性腺激素释放的作用。ＧｎＲＨ除对垂体ＬＨ／ＦＳＨ分泌有强大的调控作用外,还与性腺和胎盘的生殖功能有关［２,３］。１ＧｎＲＨ信号转导途径ＧｎＲＨ调节垂体ＬＨ...     

GnRH免疫公猪的研究进展

本文主要综述了促性腺激素释放激素(gonadotropin hormone-releasing hormone,GnRH)免疫公猪的原理和可行性,以及GnRH免疫对公猪生殖激素、睾丸、性欲和生产性能的影响,并指出今后研究的趋势和方向。     

GnRH主动免疫对SD雄鼠下丘脑GnRH合成及性腺反馈系统的影响

探讨GnRH主动免疫对SD雄鼠下丘脑GnRH合成及性腺反馈系统的影响。36只SD雄鼠随机分为免疫组、手术去势组及对照组,免疫组于12周龄时初免,8周后加免。放免法测定血清抗体滴度、激素浓度及下丘脑正中隆起GnRH含量,实时荧光定量PCR分析下丘脑生殖相关基因mRNA的变化。结果显示,GnRH主动免疫后12只免疫鼠中11只血清GnRH抗体滴度显著升高,血清LH、FSH及T浓度显著降低(P<0.05),睾丸严重萎缩(免疫去势鼠)。与对照鼠相比,免疫去势显著降低下丘脑GnRH含量(P<0.01),且显著下调下丘脑雌激素α受体(ERα)、雄激素受体(AR)、Kiss-1、GPR54及GnRH的mRNA表达水平(P<0.05)。手术去势鼠除血清LH、FSH浓度及下丘脑ERα的mRAN表达水平显著高于对照鼠外(P<0.05),其余指标均与免疫去势鼠类似。结果首次表明,GnRH主动免疫抑制性腺负反馈调节作用及降低了下丘脑GnRH的合成。     

应用GnRH+PGc+GnRH法诱导水牛同期发情效果的观察

为了提高水牛的繁殖力,研究利用氯前列烯醇(PGc)结合促性腺激素释放激素(GnRH)对水牛群体进行同期发情处理,比较不同PGc浓度、不同药物组合、不同年龄和不同品种对同期发情效果的影响。结果表明:不同剂量的PGc对水牛的同期发情率存在显著差异(P0.05),以0.6 mg的PGc注射量为宜。注射800 IU孕马血清促性腺激素(PMSG)+PGc 0.6 mg试验组的水牛同期发情率优于500 IU PMSG+PGc 0.6 mg试验组,但低于GnRH+PGc+GnRH试验组的水牛同期发情率,且差异显著(P0.05)。GnRH+PGc+GnRH法可促进不同年龄和品种的水牛同期发情效果,且差异显著(P0.05),因此采用GnRH+PGc+GnRH法可促进水牛的同期发情,进而提高水牛的繁殖力。     

Cloning,expression, and polymorphism at the 5ʹ-flanking region of the GnRH gene and their association with laying traits in Muscovy duck (Cairina moschata)

1. Gonadotropin-releasing hormone (GnRH), a neuropeptide, plays a vital role in the hypothalamus–pituitary–gonadal (HPG) axis. In vertebrates, GnRH is crucial for the onset of sexual development and the entire reproductive process. The purpose of this study was to identify genetic factors associated with egg-laying traits of Muscovy ducks.

2. The full-length cDNA (474 bp) of Muscovy duck GnRH was obtained and characterised. It encodes 92 amino acids containing a 1-amino acid signal peptide cleavage site. Phylogenetic analysis revealed that Muscovy duck GnRH has a close relationship with Anas platyrhynchos GnRH.

3. GnRH showed significantly different expression profiles between 4 developmental periods in the hypothalamus, pituitary, and ovary. The expression of GnRH in the laying period (36 weeks) was higher than at other periods in the three tissues. GnRH was widely expressed in 12 examined tissues of nesting and laying Muscovy ducks. In the hypothalamus, pituitary and gonads, the expression of GnRH was higher than in other tissues.

4. In laying Muscovy ducks, the expression of GnRH in the hypothalamus, pituitary, ovary, muscular stomach, pancreas, heart, duodenum and spleen was significantly higher than in nesting dusks. Differences were detected in the liver and glandular stomach between laying ducks and nesting ducks. Differences between the kidney and lung were not significant.

5. In the pituitary, the GnRH and GnRH receptor (GnRHR) genes shared the same expression profiles during 4 time points. Both genes had the highest expression at 36 weeks of age.

6. A mutation (g.206G > A) in the 5?-flanking region was associated with egg-laying performance. Individuals with genotype GG had better egg-laying performance than the individuals with genotype AA. GnRH may be used as a marker gene for laying performance in the Muscovy duck.

     

使用GnRH提高产后奶牛繁殖率

产后早期使用 GnRHGnRH 能刺激垂体释放 LH,已用作提高繁殖效率的辅助手段。产后早期(产后10—20天),使用 GnRH能激发卵巢活动,促进早期恢复性周期活动。在产后12—18天,肌注100μg GnRH,结果首次发情时间提早,一次妊娠配种次数及空怀天数     

GnRH在母牛繁殖中的应用

一、用于母牛超排促性腺释放激素(GnRH)和其它激素配合使用,可以显著地提高超排效果。金川(1983)对黑白花青年母牛投与2500国际单位的孕马血清激素(PMSG),并于第一次人工授精时分两次给与促黄体素-释放激素(LH-RH),确认可以提高排卵数和回收卵数,但     

家畜GnRH免疫去势的研究进展

对家畜来说,去势有其必要性.完整公猪肉中有一种难闻的"膻味"(主要成分是雄烯酮和粪臭素);公牛、公羊性情暴躁凶悍,相互格斗,容易造成外伤感染,而且肉质嫩度差、质地粗糙、质量等级低;母牛在性成熟后18-24 d会出现周期性发情,易在牛群中引起混乱,导致无计划怀孕而影响育肥效果.     

GnRH在母牛繁殖中的应用

<正> 一、用于母牛超排 GnRH和其它激素配合使用,可以显著地提高超排效果。金川(1983)对黑白花青年母牛投与2500 IU的PMSG,并于第一次人工授精时分两次给予LH—RH—EA,确认可以提高排卵数和回收卵数,但PMSG剂量增至3000 IU时,投与LH—RH—EA则无效果。苏联beaTe(1983)用PMSG或     

GnRH在奶牛产后的应用

产后12—18天给患分娩期疾病的母牛应用GnRH(Gn释放激素)时,出现发情的时间较未处理的对照牛为早,每次受胎的配种次数以及空怀的天数也较少。对胎衣停滞的母牛,应用GnRH处理,其产犊到受胎的间隔较未处理的对照牛为短,每次受胎的配种次数也较少。给屡配不孕的母牛输精时,应用GnRH能提高受胎率。     

绵羊GnRH受体表达的调节

简述绵羊ＧｎＲＨ受体基因的分子特征及其表达的调节。ＧｎＲＨ受体ｍＲＮＡ的表达在排卵前促性腺激素峰之前增加，峰后下降。Ｅ２对ＧｎＲＨ受体表达具有促进作用。关于孕酮的作用尚未达表具有促进作用。关于孕酮的作用尚示达成共识。     

GnRH在产后奶牛上的应用

患围产期障碍的母牛,在产后12—18天给予GnRH,要比未处理的对照母牛发情更早,每次受孕的配种次数更少,空怀的天数更短。在患胎衣不下的母牛中,经GnRH处理的那些较未处理的对照牛,产犊至受孕的间期更短,每次受孕的配种数也更少些。屡配不孕母牛在授精时应用GnRH能够使受孕率提高。有人指出,奶牛繁殖的目标应该是:能在产后3周前开始出现发情周期,到产后4周时子宫已经复旧且无感染,在配上以前的第二个发情周期及其随后的每个发情周期,都显示行为发情,并能够在产后50—85天的第一次配种时受孕。促性腺素释放激素(GnRH),因已证实能够刺激垂体促黄体素(LH)的释放,所以将其列为提高产后奶牛繁殖性能的辅助剂。GnRH应用的主要方面(除治疗卵巢囊肿外)还有发动产后早期(产后10—20天)的卵巢治动,或在授精时给予以提高受孕率。