抑制素受体研究进展

抑制素受体目前还没有确定,本文论述了有关抑制素受体的三种假说及抑制素与受体作用的假说,目的是为该受体以后的研究奠定理论基础。     

抑制素受体研究进展

抑制素受体目前还没有确定,本文论述了有关抑制素受体的三种假说及抑制素与受体作用的假说,目的是为该受体以后的研究奠定理论基础。     

抑制素研究进展

IB(Iinhibin，抑制素)主要由雌性动物卵巢颗粒细胞和雄性动物睾丸的Sertoli细胞分泌。研究结果表明，抑制素具有内分泌和旁分泌物的作用：既可通过复杂的反馈机理，调节体液FSH水平，又可通过局部作用，对卵巢内卵泡发育发挥调节作用。因此，近年来学者们做了大量关于抑制素的研究。本文主要论述了抑制素的研究应用情况。     

抑制素免疫对动物生殖功能影响的研究进展

抑制素是一种主要由动物性腺分泌的异二聚体蛋白激素 ,它通过选择性抑制垂体促性腺激素 (主要是 FSH)的分泌 ,进而影响动物的生殖活动。而利用抑制素对动物主动或被动免疫 ,可增加排卵率 ,提高繁殖力的独特功能越来越受到人们的重视。本文就近年来有关抑制素免疫对动物生殖功能影响的研究作一综述。1　抑制素的类型在抑制素免疫研究中 ,有 3种形式的免疫原 ,即天然抑制素制剂、合成抑制素肽段和重组型抑制素。1 .1　天然抑制素　主要有牛抑制素 ( b MPI)和羊抑制素 ( o MPI) ,它是用一种单克隆抗体 2 56 H(其具有对牛 3 2 KD抑制素特异…     

抑制素研究进展

抑制素是一种主要由性腺分泌的糖蛋白激素,对ＦＳＨ起负反馈调节物作用。由于其具免疫原性,外源抑制素通过免疫调节可降低体内抑制素的生物活性,导致ＦＳＨ浓度升高,使排卵率和产仔数增加,近年来其作为多胎疫苗的角色已越来越为人们所重视。本文介绍了抑制素的生物学特性,还回顾了抑制素的几种主要测定方法,着重综述了抑制素对雌、雄动物生殖机能的调节作用。     

公畜抑制素及其研究

抑制素(Inh ib in,IB)是一种由雌性卵泡颗粒细胞和雄性睾丸支持细胞分泌的糖蛋白激素,由α和β亚基组成的二聚体,其主要生理作用是特异性地调控垂体FSH(促卵泡素)的分泌。自1932年Macullagh提出这个概念以来,动物抑制素的研究日益受到人们的重视。目前对哺乳动物抑制素合成的部位、分子结构及生理作用已经有了深入的认识,利用蛋白质分离及分子原位杂交技术已人工合成了牛、羊、人的重组抑制素,固相合成技术已成功地合成了有功能的α片段N端     

抑制素免疫的研究进展

本文参阅了近年来国内外对抑制免疫的研究资料，归纳介绍了抑制素免疫的研究进展，并在此基础上，提出了进一步研究的任务。     

抑制素研究进展

IB(Iinhibin,抑制素)主要由雌性动物卵巢颗粒细胞和雄性动物睾丸的Sertoli细胞分泌。研究结果表明,抑制素具有内分泌和旁分泌物的作用:既可通过复杂的反馈机理,调节体液FSH水平,又可通过局部作用,对卵巢内卵泡发育发挥调节作用。因此,近年来学者们做了大量关于抑制素的研究。本文主要论述了抑制素的研究应用情况。     

肌肉生成抑制素基因的研究进展

肌肉生成抑制素(MSTN)属TGF-β超家族成员之一,主要分布在骨骼肌,对肌肉生长起负调控作用,MSTN的研究在畜牧业及医学领域具有重要意义.作者就MSTN的发现、分布、结构、生物学功能、作用机制及影响MSTN的因子如生长激素、生长分化因子11、T-cap蛋白、卵泡发育素、类胰岛素高亲和性结合蛋白、生肌决定因子等进行了综述,并展望了MSTN研究的发展趋势和应用前景.     

抑制素免疫对羊生殖的影响

抑制素是一种主要由动物性腺（睾丸的支持细胞和卵巢的颗粒细胞）分泌的一种异二聚体糖蛋白激素,由两个二硫键连接两个不同的亚单位（α和β）构成。抑制素对垂体ＦＳＨ的分泌和／或合成具有选择性地抑制作用。抑制素免疫中和技术能特异性地刺激ＦＳＨ分泌,进而促进配子生成,提高动物繁殖力。西方把抑制素免疫对羊排卵率、产羔数、初情期、超数排卵和公羊繁殖性能的影响作一综述。     

鸡肉品质营养调控的研究进展

<正>近年来,随着社会经济的快速发展,人民生活水平日益提高,消费者对鸡肉品质提出更高要求,不仅要求安全卫生、营养价值高,而且还要求肉质和风味     

马立克氏病的研究进展

鸡马立克氏病(Marek'sDisease,MD)是由马立克病毒引起鸡的一种淋巴组织增生性疾病.以病鸡的外周神经、性腺、虹膜、各种内脏器官、肌肉和皮肤发生单核细胞浸润、形成淋巴肿瘤为特征.本病传播速度快,传播面积广,潜伏期长(1～6个月不等).患急性内脏型鸡马立克氏病的鸡群淘汰及死亡率高达8%一30%.严重发病的鸡群可造成全群覆灭,OIE将其列为B类疫病.     

卵泡抑制素主动和被动免疫及基因免疫研究进展

抑制素是由动物卵巢颗粒细胞或睾丸间质细胞分泌的糖蛋白激素 ,对垂体FSH的分泌具有抑制作用。用抑制素或其片断主动或被动免疫可以提高家畜的排卵率和产仔数 ;用抑制素基因免疫可望得到类似效果。本文通过分析抑制素的理化特性、生物学作用及作用机制、主动和被动免疫对家畜繁殖力的影响 ,阐述了抑制素基因免疫的原理与方法及应用前景     

Antiserum to an inhibin alpha-chain peptide neutralizes inhibin bioactivity and increases ovulation rate in sheep.

A synthetic fragment representing the N-terminal 25 amino acid residues of the alpha-subunit of ovine inhibin (alpha-IF) was coupled to human alpha-globulin (h alpha-G) and used as an antigen. In Exp. 1, ovine antiserum generated against alpha-IF-h alpha-G was shown in vitro to neutralize inhibin bioactivity contained in ovine follicular fluid. In Exp. 2, 18 lambs were immunized with .3, .6 and 1.2 mg alpha-IF-h alpha-G or equivalent doses of h alpha-G. Antibody titer to alpha-IF was detected only in serum from lambs immunized against alpha-IF-h alpha-G and was first detected 27 +/- 2 d after primary immunization. Thereafter, antibody titers increased steadily. The degree of antibody responses was unrelated to antigen dose and differed among lambs. Plasma FSH concentrations were unchanged, whereas LH concentrations were lower (P less than .001) in sheep immunized against alpha-IF-h alpha-G. Ovulation rate was increased (3.5 +/- .5 vs 1.5 +/- .1; P less than .01) in lambs immunized against alpha-IF-h alpha-G. Ovulation rate was similar among animals receiving different antigen doses and increased with time after primary immunization (P less than .01). At estrous periods occurring approximately 34, 50, 74 and 107 d after primary immunization, respective ovulation rates were 157, 169, 207 and 450% of control values. Ovulation rate and antibody titer were correlated positively (pooled r = .95; P less than .01) within lambs. In Exp. 3, three lambs were immunized with .25 mg unconjugated alpha-IF; this was nonantigenic. In conclusion, the use of a synthetic fragment of the alpha-subunit of ovine inhibin as a hapten elicits an antibody capable of neutralizing inhibin bioactivity in vitro and increasing ovulation rate in vivo.     

Production of inhibin A and inhibin B in boars: changes in testicular and circulating levels of dimeric inhibins and characterization of inhibin forms during testis growth

We investigated the production of inhibin in boars from the infantile to pubertal periods by: (1) measurement of testicular and circulating levels of inhibin, (2) characterization of inhibin forms and (3) localization of inhibin subunits in the testis. Total inhibin levels in the testis increased until 8 weeks of age but then declined to much lower values at 15 weeks. Testicular inhibin A and inhibin B were high until 8 weeks. Circulating levels of total inhibin and inhibin A were also high until 8 weeks, then declined from 10 weeks; inhibin B was not detected, because of low sensitivity of the inhibin B assay. Analyses of inhibin A and inhibin B levels in the eluted fractions obtained from testes after immunoaffinity chromatography and SDS-PAGE showed the presence of a peak of approximately 45 kDa until 10 weeks of age. As the boars aged, the levels of inhibin A and inhibin B increased in the molecular weight region of 29–31 kDa. The fractions corresponding to 29 and 30 kDa suppressed FSH release from rat pituitary cells, but the 45 kDa fraction had no FSH-suppressing activity. Total amounts of inhibin A isolated from the SDS gels were similar to those of inhibin B until 10 weeks of age, but were three times higher than those of inhibin B between 15 and 25 weeks. Further fractionation by reverse phase high-performance liquid chromatography revealed that the 29–31 kDa immunoreactive material was composed of mature forms of inhibin A and inhibin B, in addition to a 26 kDa monomer. Immunohistochemistry indicated that positive immunostaining for the subunits was observed in Sertoli cells from the infantile to pubertal periods. Elongated spermatids also showed positive signals at age 25 weeks. These results clearly indicated that: (1) the boar testis has the ability to produce inhibin A and inhibin B during the infantile period but inhibin A is the predominant form towards puberty and (2) the molecular weight forms of inhibin and the sites of production of inhibin change with testicular development.     

Dimeric inhibin concentrations in mares with granulosa-theca cell tumors

OBJECTIVE: To determine whether concentrations of dimeric inhibin (CaCA) are greater in plasma and tumor fluid from mares with granulosa-theca cell tumors (GTCT), compared with concentrations in plasma and equine follicular fluid (eFF) from control mares. ANIMALS: 6 mares with GTCT and 12 clinically normal mares. PROCEDURE: The alphabetaA immunoradiometric assay used 2 antibodies, one against each subunit of inhibin (alpha and betaA subunits). Tumor tissue, tumor fluid, and a single blood sample were collected at the time of surgical removal of the GTCT. A single blood sample was collected from 7 control mares during various stages of the estrous cycle. Five other control mares were ovariectomized when their ovaries contained growing follicles of 25 to 35 mm in diameter. A blood sample and eFF from the largest follicle were collected at the time of ovariectomy. RESULTS: Mares with GTCT had significantly greater plasma concentrations of betabetaA (mean +/- SEM, 0.86 +/- 0.53 ng of recombinant human-alphabetaA/ml), compared with control mares (0.14+/-0.02 ng/ml). Concentrations of alphabetaA in tumor fluid and eFF were similar. Concentrations of alphabetaA were significantly lower after ovariectomy. CONCLUSIONS AND CLINICAL RELEVANCE: Dimeric inhibin concentration was higher in plasma from mares with GTCT than in plasma from control mares. Increased granulosa cell mass and loss of mechanisms regulating alphabetaA release in mares with GTCT likely accounted for the increase in plasma concentrations. Measurement of alphabetaA concentrations may be useful for identifying mares with GTCT.     

卵泡抑制素在家禽养殖中的研究应用

抑制素(Inhibin,INH)又称卵泡抑制素(Folliculostatin)或性腺抑制素(Gonadostatin),是一种主要由雌、雄动物性腺分泌的一种水溶性多肽激素,由α和β亚单位组成。由于其具有免疫原性,外源卵泡抑制素通过免疫调节可以降低家禽机体内卵泡抑制素的生物活性,导致机体循环中促卵泡素(FSH)浓度升高,使排卵率和产蛋率增加。国外已从鸡、鸭、人类卵泡液等中分离提纯得到具有卵泡抑制素活性的α亚单位片断,体外生化合成也获得了成功,并利用cDNA技术已生产出卵泡抑制素融合蛋白,且证明这些卵泡抑制素产物均具有选择性地抑制脑垂体体内外FSH产生和…     

假俭草研究进展

综述了假俭草品种选育、形态学、坪用价值、抗寒性和分子标记的研究进展,提出假俭草抗寒性是其坪用价值的限制因素。     

胃泌酸调节素研究进展

胃泌酸调节素(OXM)是由小肠L细胞分泌的一种肽类激素,它能够透过血脑屏障到达下丘脑弓状核,与其特异性受体结合后发出饱感信号终止动物进食.胃泌酸调节素对动物食欲的调节和内环境稳态的稳定,是通过抑制胃酸分泌、降低采食量、增加能量消耗及动员脂肪分解等生物学功能实现的.论文综述了近年来国内外学者对胃泌酸调节素在来源及结构、生物学功能和作用机理3个方面的研究成果,并阐述了对其进行进一步研究的发展方向.     

防御素研究进展

防御素是广泛分布于动物和植物界的一类富含半胱氨酸的阳离子内源性抗微生物肽,是内源性抗微生物肽中的一个大家族。根据防御素分子内半胱氨酸的位置和连接方式、前体性质及表达位置的差异,可分为α-防御素、β-防御素、θ-防御素、昆虫防御素和植物防御素5种类型。防御素是由29个~54个氨基酸残基组成的小分子肽,具有广泛的生物学活性。防御素分子可以直接作用并杀死细菌、真菌和病毒等病原微生物,除此之外,防御素还具有细胞毒、免疫调节以及创伤和神经损伤的修复等多种生物学活性。文章概述了防御素的分子结构特征、分布、生物学活性及国内外研究概况。