促性腺激素释放激素及其类似物的功能与应用

促性腺激素释放激素（gonadotropin releasing hormone，GnRH）是主要由下丘脑合成的直链十肽激素，以脉冲形式分泌进入丘脑下部垂体门脉系统到达垂体前叶，或进入神经分泌轴突末端，调控垂体促卵泡激素（follicle-stimulating hormone，FSH）、促黄体素（1uteinizing hormone，LH）的合成与分泌。它是神经、免疫和内分泌调节系统相互联系的重要信号分子，与性腺和胎盘及生殖功能密切相关。     

TGF-β家族成员调控家禽卵泡发育的研究进展及展望

与哺乳动物不同,家禽的卵泡发育无明显发情周期,其卵泡发育遵循严格的等级发育体系。禽类卵泡的等级发育是一个复杂的调节过程,受卵泡细胞内外的内分泌激素、自分泌/旁分泌因子的共同调节。促卵泡刺激素(Follicle stimulating hormone,FSH)和促黄体激素(Luteinizing hormone,LH)在调控卵泡发育、卵母细胞成熟和排卵中起着重要的作用。此外,局部产生的生长因子如转化生长因子β超家族(Transforming growth factor superfamily,TGF-β)成员,包括抗缪勒氏激素(Anti-Müllerian hormone,AMH)、骨形态蛋白家族(Bone morphogenetic proteins,BMPs)、抑制素(Inhibin)和激活素(Activin)等,与促性腺激素一起协同调控卵泡的生长发育、卵母细胞的成熟等过程。文章综述了TGF-β家族成员,包括AMH、BMPs、抑制素、激活素在家禽卵泡发育中的作用及其未来的研究方向。     

生殖激素在畜牧生产中的应用（综述）

实践中一般把直接作用于生殖活动，与生殖机能关系密切的激素统称为生殖激素。这些激素有的来源于生殖器官之外的组织或器官，有的则是生殖器官本身所产生的。例如，下丘脑促性腺激素释放激素，来自垂体或胎盘的促性腺激素（促卵泡素、促黄体素、孕马血清促性腹激素、绒毛膜促性腺激素等）及两性性腺所产生的激素等。基于这些生殖激素在生产中有重要应用价值，我们根据这些生殖激素的来源和生理功能以及生产实践应用实例略谈几点。1神经激素（如下丘脑分泌的释放激素、催产素等）1．1促性腺激素释放激素（CnRH）。这种激素可以引起垂体促…     

利用激素诱导青年母猪发情及人工授精的受胎效果观察

孕马血清促性腺激素（血促性素）PMSG具有促卵泡素（FSH）和促黄体素（LH）的功能,主要是FSH功能,能促卵泡发育、成熟。人绒毛膜促性腺激素（绒促性素）hCG具有促黄体素（LH）和促卵泡素（FSH）的功能,主要是LH功能,能促卵泡成熟、排卵。二者协调可以使处于卵巢静止的青年母猪卵泡发育、成熟、排卵。     

家禽卵巢主要生殖激素受体的研究进展

生殖激素对于家禽卵泡发育、排卵、受精等生理功能具有重要的影响。家禽生殖激素通过与其受体的结合,在家禽生长发育和生殖过程中发挥至关重要的作用。本文对禽类卵巢促性腺激素释放激素受体(Gn RHR)、促卵泡刺激素受体(FSHR)、促黄体激素受体(LHR)、雌激素受体(ER)、孕酮受体(PR)和雄激素受体(AR)等六种主要生殖激素受体的结构、分布和生理功能等方面进行了综述,希望给家禽生产与繁殖的研究工作提供帮助。     

动物促性腺激素的介绍

1垂体促性腺激素垂体是重要的神经内分泌器官,可以分泌多种蛋白质激素来调节动物的生长、发育、代谢,以及生殖活动。现已发现腺垂体至少分泌7种激素,即生长激素、促肾上腺皮质素、促甲状腺素、促乳素、促卵泡素、促黄体素、粗黑色细胞素。     

家禽与家畜繁殖生理差异的对比分析

在畜禽生产中，繁殖力是生产水平的决定因素之一，而家禽和家畜在繁殖方面有很大的差异，了解它们之间的差异有助于我们根据其各自特点采取相应措施，提高繁殖效率。１生殖激素方面的差异１．１丘脑下部激素在猪的丘脑下部存在有促乳素释放因子（PRF）和促乳素抑制因子（PTF），两者协同对垂体前叶促乳素（PRL）的合成和释放起调节作用。鸡的丘脑下部仅存在有促乳素释放因子（PRF），而不存在促乳素抑制因子（PTF），PRL的合成和释放仅受PRF的调控。１．２孕激素猪的孕激素主要是卵巢上排卵后的卵泡内形成的黄体分泌的，在其妊娠过…     

生殖激素—PMSG在临床上应用效果

生殖激素──ＰＭＳＧ在临床上应用效果生殖激素ＰＭＳＧ，是一种糖蛋白激素，功能和垂体所分泌的促卵泡素相似，有明显的促卵泡发育作用，还含有类似促黄体素的成份，因此有促使排卵和黄体形成的功能。早期断奶母猪和乏情母猪使用该种激素有明显的促发情作用，我们牧场第...     

母牛常用生殖激素的临床应用

近年随着产奶水平的不断提高,在一些高产奶牛群中,因生殖激素失调而引起的繁殖障碍亦有所增多。在临床治疗内分泌紊乱的不孕母牛过程中,由于缺乏对生殖激素的全面了解,而使用不当,不能取得预期效果,甚至出现一些不良反应。现将本场近年来母牛常用生殖激素的临床使用方法简介如下。1母牛常用的生殖激素种类1.1来自下丘脑的促性腺激素释放激素(GnRH)其主要功能为:促进和调节脑垂体前叶的分泌和释放促黄体素(LH)、促卵泡素(FSH)。临床用药以LRH-A3(促排Ⅲ)为多。1.2来自垂体前叶的促性腺激素主要有两种:一是促进卵泡发育和成熟的促卵泡素(…     

抑制素、活化素和卵泡抑素研究进展

抑制素、卵泡抑素和活化素是3种参与垂体促卵泡素调控过程的糖蛋白激素,随着对促卵泡素调控过程的深入了解,发现这3种蛋白在动物生殖周期中发挥着重要的作用。文章主要就抑制素、卵泡抑素和活化素的结构特征、生理功能以及抑制素和卵泡抑素对活化素生物学活性的抑制机理进行了综述。     

雌禽生殖生理研究进展

禽类与哺乳动物相比,在生殖解剖学构造和生理学机能方面有其独特性。作者系统阐明了雌禽卵泡发育过程和排卵机理,并对其生殖内分泌学调控特点进行论述,为提高家禽繁殖性能提供了参考依据。     

Avian reproductive endocrinology.

Hypothalamic-releasing factors regulate the secretion of anterior pituitary hormones. The anterior pituitary gland secretes the same six hormones as found in mammals: FSH, LH, prolactin, GH (somatotropic hormone), ACTH, and TSH, plus the melanotropic hormone. The endocrine hormones of the avian posterior pituitary gland concerned with reproduction are mesotocin and AVT. The pineal gland, through the secretion of the hormone melatonin, modulates the periodic autonomic functions of the central nervous system. The ovary produces estrogens, progestogens, and androgenic compounds. The testes produce testosterones and progesterone. The thyroid glands produce two hormones, T4 and T3. The avian adrenal glands produce corticosterone and aldosterone. The bursa of Fabricius is considered an endocrine organ since it is involved in the production of humoral factors. The male reproductive system undergoes hormonal changes associated with puberty, the breeding season, and molt. Some avian species undergo a type of disintegration and seasonal reconstruction of the testis and epididymis. The relationship of the ovarian follicular hormones and the plasma hormones varies depending on the stage of the reproductive cycle and the seasonal photostimulation. Female birds may conceive in the absence of a mate as a result of the fertile period phenomena. The blood chemistry of laying birds is different from that seen in nonlaying hens. Domestication has had a definite influence on the hormone cycles of some avian species. This may lead to certain reproductive problems.     

Physiology, diagnosis, and diseases of the avian reproductive tract.

Disorders of the reproductive system represent a large portion of both large and small domestic animal medicine. Although some disorders of this system have been extensively studied in birds, this science is still in its infancy, when compared to mammalian reproductive medicine. This may be due to several reasons, but the simple fact that birds are oviparous renders knowledge of mammalian reproductive anatomy, histology, physiology, and disease process, inapplicable to avian patients. Nevertheless, several specific diseases or conditions affecting the reproductive system of birds have been described. By integrating information about the comparative anatomy and physiology of birds, reports of the most common reproductive diseases of birds and utilizing the latest diagnostic techniques, especially videoendoscopy, the avian practitioner should be able to diagnose and properly treat a high percentage of the avian reproductive diseases.     

上海地区野鸟和家禽中PRRSV抗体的血清学调查

2005年3～5月，采用ELISA法对来自于上海地区的208份野鸟和357份家禽的血清样品进行了猪繁殖和呼吸综合征病毒（porcine reproductive andrespiratory syndrome virus，PRRSV）抗体的血清学调查。结果表明，受检的5种家禽存有不同程度的抗体阳性率，而野鸟的阳性样品集中于绿头鸭和麻雀。     

Update on neuroendocrine regulation and medical intervention of reproduction in birds.

In avian species, reproductive disorders and undesirable behaviors commonly reflect abnormalities in the neuroendocrine regulation of the reproductive system. Current treatment options are often disappointing, show no long-lasting effect, or have significant side effects. A possible reason for our lack of success is a dearth of knowledge of the underlying neuroendocrine, behavioral, and autonomous physiology of the reproductive processes. Tremendous progress has been made in the last few years in our understanding of the neuroendocrine control of reproduction in birds. Advantage should be taken of these experimentally derived data to develop appropriate and safe treatment protocols for avian patients suffering from reproductive disorders.     

Isolation and prevalence of Campylobacter in the reproductive tracts and semen of commercial turkeys

Campylobacter is one of the most commonly reported bacterial causes of human foodborne infections in the United States, and epidemiologic evidence indicates that a significant proportion of human infections result from the improper preparation of poultry products. Campylobacter frequently colonizes the avian intestinal tract, but recent research indicates that this organism can also colonize the avian reproductive tract and possibly contaminate eggs and subsequent offspring. The present studies were undertaken to determine the prevalence of Campylobacter in the reproductive systems of commercial turkeys. In the first study, pooled semen samples from seven commercial turkey farms were randomly collected by abdominal massage over a period of 13 wk. The pooled semen samples were serially diluted, and 0.1 ml of each dilution was plated on Campy-Line agar and incubated at 42 C for 48 hr in a microaerophilic environment for enumeration of Campylobacter. Campylobacter was isolated from 57 of the 59 pooled semen samples, and levels ranged from below the limit of detection (<10(1)) to 1.6 x 10(6) cfu/ml of semen. In the second study, the reproductive tracts of 11 hens and 17 toms were aseptically excised, and the segments (female: vagina, shell gland, isthmus, magnum, and infundibulum; male: ductus deferens and testes) were swabbed with a dry cotton sterile swab. The swabs were incubated for 24 hr in Campylobacter enrichment broth, and 0.1 ml of the enriched sample solution was streaked onto Campy-Line agar plates and incubated at 42 C for 48 hr in a microaerophilic environment. Of the 11 hens sampled, Campylobacter was isolated from the vagina (10/11), the shell gland (7/11), the isthmus (8/11), the magnum (6/11), and the infundibulum (4/11). Of the 17 toms sampled, Campylobacter was isolated from the ductus deferens (8/17) and the testes (2/17). Campylobacter is present in the reproductive tracts and semen of commercial turkeys and may lead to vertical transmission of Campylobacter from the hen to the chick.     

Sperm Storage in the Female Reproductive Tract in Birds

The ability to store sperm in the female genital tract is frequently observed in vertebrates as well as in invertebrates. Because of the presence of a system that maintains the ejaculated sperm alive in the female reproductive tract in a variety of animals, this strategy appears to be advantageous for animal reproduction. Although the occurrence and physiological reasons for sperm storage have been reported extensively in many species, the mechanism of sperm storage in the female reproductive tract has been poorly understood until recently. In avian species, the specialized simple tubular invaginations referred to as sperm storage tubules (SSTs) are found in the oviduct as a sperm storage organ. In this review, we summarize the current understanding of the mechanism of sperm uptake into the SSTs, maintenance within it, and controlled release of the sperm from the SSTs. Since sperm storage in avian species occurs at high body temperatures (i.e., 41 C), elucidation of the mechanism for sperm storage may lead to the development of new strategies for sperm preservation at ambient temperatures, and these could be used in a myriad of applications in the field of reproduction.     

Impact of endocrine disrupting chemicals on reproduction in Japanese quail

Many environmental contaminants can interact with the endocrine system, thereby potentially disrupting the reproductive fitness of individuals. In avian species, the egg-yolk is a major route for excretion of lipophilic compounds by the adult female bird and embryos are exposed to contaminants that have been deposited in the eggs. The reproductive and neuroendocrine system of Japanese quail undergoes sexual differentiation during embryo development. The phenotypic sex, including sex-specific adult behavior, is hormonally imprinted already before hatching. The sexual differentiation of the brain in quail is sensitive to estrogens and the presence of estrogen results in a female phenotype. The relatively low concentration of estrogens in male embryos, on the other hand, results in a male behavioral phenotype. The behavior of male quail can be demasculinized by estrogen exposure during the period of sexual differentiation, and estrogen-exposed males are not able to display a male-typical behavior as adults. Also, differentiation of the reproductive organs is sensitive to hormones during embryogenesis, and an excess of estrogens can for instance induce persistent morphological changes in the reproductive organs of females. Our research has focused on effects in adult birds after embryonic estrogen exposure. We have studied sexual behavior and other reproductive variables in adult quail after in ovo injection of known and suspected estrogenic compounds. Synthetic estrogens and insecticides, such as o,p'-DDT altered the development of the neural system and resulted in demasculinization of male quail. In females, o,p'-DDT caused morphological changes of the oviduct and egg laying was reduced. Our studies suggest that the neural system and the female reproductive system of avian embryos are very sensitive to the effects of chemicals with estrogenic activity.     

Avian Reproductive Disorders

Avian reproductive disorders are commonly diagnosed in pet birds, backyard flocks, and commercial aviaries. Birds that are diagnosed with reproductive disorders can present with a variety of clinical signs that range from benign disorders to life-threatening emergencies. In many cases there are underlying husbandry and management issues that need to be addressed. This article will address the presenting signs of common reproductive disorders in avian species and the best approaches to determine appropriate diagnostic and treatment plans.