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-激活素-卵泡抑素系统及其受体的研究进展

抑制素-激活素-卵泡抑素系统是卵巢卵泡内重要的局部调节因子,通过内分泌机制调节垂体卵泡刺激素的分泌,经自分泌和旁分泌调节卵巢卵泡的发育、闭锁和黄体化过程,进而调节哺乳动物的生殖活动.抑制素受体和激活素受体的发现使得对抑制素-激活素-卵泡抑素系统有了深入的研究.本文对抑制素-激活素-卵泡抑素系统,抑制素受体和活化素受体的...     

激活素、抑制素及其受体与动物生殖作用的研究进展

激活素和抑制素均属于转化生长因子β(TGF-β)超家族成员的多功能生长和分化因子,具有多种生物学功能及广泛的生物学活性,其生理功能是通过受体与靶器官结合而实现的。作者主要就抑制素、激活素的结构特征、生理功能和对生殖的作用及其与受体的作用方式进行综述。     

抑制素的功能与作用机理探讨

抑制素是人和动物的许多器官和组织分泌的一种糖蛋白激素，其中动物性腺细胞（卵巢的颗粒细胞和睾丸的Sertoli细胞）所分泌的含量较多，由于抑制素在医学生殖领域和畜牧业中具有广泛的用途，所以作者从不同的角度对它的功能与作用机理作了以下探讨：（1）自分泌和旁分泌机理；（2）G蛋白的介导作用；（3）促性腺激素合成与降解理论；（4）阈值理论；（5）抑制素作于下丘脑，这些假说对了解和运用抑制素有一定的作用。     

禽类卵泡抑制素研究现状

抑制素（Ｉｎｈｉｂｉｎ，以下简称ＩＢ）是一种由性腺分泌的糖蛋白激素，它主要调控垂体ＦＳＨ（促卵泡素）的分泌。自１９３２年Ｍａｃｕｌａｇｈ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部位、分子结构及生理作用已经有了深入...     

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…     

抑制素基因免疫大鼠的免疫应答与基因表达

为了研究抑制素基因免疫对大鼠免疫应答和发情的影响及免疫后抑制素的组织分布,将60只大鼠分为5组,每只分别肌肉注射10（T1）、50（T2）、100μg pCIS（T3）,50μg pcDNA3.1（V）和生理盐水（S）。ELISA检测抑制素抗体水平,阴道涂片法检测大鼠的发情状况,免疫组化分析抑制素的组织分布。结果显示,不同剂量抑制素基因2次免疫10 d后抗体P/N值均显著升高（P〈0.05）,3次免疫10 d后T2和T3组抗体P/N值进一步显著升高（P〈0.05）,T3组抗体水平有高于T1和T2组的趋势（P〉0.05）;抑制素基因免疫对大鼠的发情无显著影响;3次免疫2周后心脏、肝脏、接种肌肉部位均未检出抑制素;卵巢、肾脏和垂体部位均检出抑制素;而脾脏部位,抑制素质粒免疫组检出抑制素,对照组则未检出抑制素。这些结果表明,免疫剂量和次数的增加没有导致大鼠产生明显的抑制素免疫耐受,抑制素基因免疫大鼠是相对安全的,抑制素的组织分布结果亦为抑制素基因免疫的作用机理研究提供了理论依据。     

抑制素及其对动物繁殖的影响

抑制素是二聚体糖蛋白激素,是机体分泌的一种能够调节促性腺激素分泌的活性物质,能够提高家畜的排卵率和繁殖力。抑制素抗原免疫可以提前动物发情,有效提高雌性动物的排卵率,对雄性动物生殖功能也起到重要的作用,因而研究抑制素对动物繁殖的影响,对于提高动物的生殖潜力有着很好的应用前景。     

抑制素的研究进展及其在家畜繁殖中的应用

<正> 前言自1932年McCullagh提出抑制素(inhibin)概念以来,动物及人性腺抑制素的研究逐渐受到各国学者的重视,但其本质性的进展则始于70年代以后。目前多数研究者认为性腺抑制素属于多肽的水溶性蛋白,对促卵泡素(FSH)的分泌起选择性抑制作用,它在生殖生理中的意义已愈来愈受到研究者的注意。 1 抑制素的理化特性从各种不同的材料中提取和纯化抑制素(牛、猪的精液,牛、羊的卵泡液等),不耐热(加热到65℃以上失活);用胃蛋白酶消化后丧失活性;不能与雄激素结合蛋白结     

抑制素免疫在提高动物繁殖力方面的应用

抑制素(Inhibin)是由Mccullagh在1932年发现的。随着人们对抑制素研究的不断深入,其逐渐被用于提高动物繁殖力。本文主要阐述抑制素的生殖生理作用、作用机理及抑制素免疫提高动物繁殖力的应用。     

北京鸭抑制素α-亚基免疫原的制备及活性研究

将重组有北京鸭抑制素α-亚基基因的T载体和pET-28a表达载体分别用NdeⅠ和XhoⅠ双酶切后连接并转化E. coli BL21(DE3),经PCR和双酶切鉴定,筛选得到阳性重组表达载体,在IPTG诱导下融合表达了北京鸭抑制素α-亚基蛋白。试验结果表明,抑制素α-亚基基因在E. coli BL21中得到了有效表达,表达产物具有免疫活性,为后期探讨该免疫原提高北京鸭产蛋性能的研究奠定基础。     

抑制素免疫对繁殖调控的影响

抑制素是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。     

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.     

猪GnRH受体基因多态性分析及相关基因组织表达谱的构建

促性腺激素释放激素(GnRH)受体基因与猪的繁殖性状密切相关,本试验对不同猪种的GnRH受体基因的编码区进行了SSCP分析,未发现多态性。在GnRH受体基因5′侧翼序列上设计引物扩增了该基因大约2000 bp的侧翼序列,通过比对设计引物,对其中的一段含有GAGABox的插入突变序列和一段由于点突变而形成转录调控蛋白结合序列IRF-1的区域运用SSCP的方法进行了多态性分析。结果表明在插入突变处,基因频率在不同的猪种间存在着很大的差异性,其中民猪与其他猪种的差异性最大。IRF突变只存在于民猪中,并且只存在AA型和AB型。构建了3头大白猪母猪GnRH基因、GnRH受体基因、卵泡抑素(FST)基因、促卵泡素(FSH)基因、FSH受体基因、促黄体素(LH)基因、抑制素(inhibin)β(a)基因、inhibinβ(b)基因的组织表达谱,根据表达谱可以推测在下丘脑-脑垂体-性腺轴外不存在这些基因表达产物的相互作用系统。     

Different origins of two corpora lutea recovered from a pregnant African elephant (Loxodonta africana)

Elephant ovaries contain multiple corpora lutea (CLs) throughout pregnancy. Two CLs (P‐1 and P‐2) collected from a pregnant African elephant were used to investigate their origin and physiological state in this study. The mRNA expressions of prolactin receptor, CYP11A and inhibin betaB subunit were higher in P‐2 than in P‐1, while LHCGR and inhibin betaA subunit mRNA were higher in P‐1 than in P‐2. Protein expression of cleaved caspase‐3 was detected in P‐1 but not in P‐2. These results suggest different origins for the two CLs in this one pregnant elephant, and we also demonstrated the production of bioactive prolactin by the elephant placenta.     

Changes in circulating and testicular levels of inhibin A and B during postnatal development in bulls

We investigated testicular and circulating levels of dimeric inhibins in Holstein bulls from the infantile to postpubertal periods (5 to 50 weeks of age) and examined the relationship between the profiles of circulating dimeric inhibins and FSH. Concentrations of total inhibin and inhibin B in the testis were highest at 4 to 5 weeks of age but decreased gradually as the bulls aged. Testicular inhibin A levels showed a gradual decline to a nadir at 15 to 26 weeks of age, but by 39 weeks, they were high again. The contents of total inhibin, inhibin A, and inhibin B per testis generally increased with age. Fractionation of testicular homogenates obtained from 15-week-old bulls by a combination of immunoaffinity chromatography and SDS-PAGE confirmed the presence of two major molecular weight forms (32 and 45 kDa) of dimeric inhibins in the testes. Circulating levels of total inhibin and inhibin A showed a significant increase in bulls at around 10 to 14 weeks of age compared to the levels between 5 and 7 weeks of age but decreased thereafter. However, immunoreactivity for inhibin B was not detected in the peripheral circulation, probably because of low sensitivity of the inhibin B assays. The concentrations of plasma FSH were high at 5 weeks of age but declined to lower levels between 11 and 40 weeks, and then increased from 41 weeks onward. There was no significant correlation between the plasma levels of FSH and inhibin A or total inhibin. The results clearly indicate that the bull testis produces inhibin A and B and secretes at least inhibin A into the circulation during postnatal development. However, the profile of circulating FSH in bulls shows no reciprocal relationship with the inhibin A or total inhibin profile during the postnatal period.     

Effects of vertically transferred 3,3',4,4',5-pentachlorobiphenyl on gene expression in the ovaries of immature Sprague-Dawley rats

We have previously shown that 3,3',4,4',5-pentachlorobiphenyl (PCB-126) vertically transferred from dams potentially exerts a direct effect on the ovaries of offspring and adversely affects female puberty. To investigate its toxicological targets in ovarian tissues, mRNAs encoding representative peptides that regulate follicular development in granulosa cells, theca cells, and oocytes were quantified using ovaries collected on postnatal days (PND) 5, 15, and 24 from the offspring of dams administered oral doses of 0, 1 or 3 microg/kg PCB-126 starting 2 weeks prior to mating and continuing until 20 days after delivery. Quantification using the real-time RT-PCR method revealed that PCB-126 lowered the amounts of mRNAs that encoded the inhibin alpha- and inhibin/activin beta A-subunits from PND 15 onwards; the amounts of mRNAs for inhibin/activin beta B-subunit, follicle-stimulating hormone (FSH) receptor, and aromatase on PND 15; and the amounts of luteinizing hormone receptor mRNA on PND 24 compared with those of the age-matched controls. In contrast, no differences were noted for mRNAs encoding c-kit, growth differentiation factor-9, bone morphogenetic protein-15, or kit ligand for any of the age groups examined. The serum FSH level on PND 24 was higher than that in the control. Since the earliest effects on the mRNAs in the rat ovaries were observed in those expressed in the granulosa cells of the growing follicles after the antral follicles had developed, molecules in granulosa cells but not in oocytes during the early stages of the antral follicles might be the primary targets of vertically transferred PCB-126.     

母鸡抑制素的产生

母鸡抑制素主要是由排卵前卵泡颗粒细胞产生的,肾上腺是又一来源,ＬＨ在刺激体外颗料细胞产生抑制素方面的比ＦＳＨ有效。去除排卵前卵泡后,血浆免疫活性抑制素显著降低,而血浆ＦＳＨ急剧升高。卵泡颗粒层中,抑制素α亚基比β（Ａ）亚基表达充分。α亚基是由近似１．７ｋｂ的ｍＲＮＡ编码,主要的８．４ｋｂβ（Ａ）－ｍＲＮＡ带在排卵前卵泡的颗粒层中表达。     

Inhibin: Regulation of reproductive function and practical use in females

Inhibins are gonadal glycoprotein hormones selectively and potently inhibiting follicle‐stimulating hormone (FSH) secretion from the pituitary gland. Inhibins are produced mainly by the ovary and are purified from follicular fluid. Inhibins were shown to be produced in two forms through dimeric assembly of an α‐subunit and one of two closely related β‐subunits to form inhibin A (α‐βA) and inhibin B (α‐βB). Although inhibin subunits are expressed in various tissues, the gonads are the major source of circulating inhibins. While inhibins may act as a paracrine or autocrine factor in some tissues, their best understood roles are as endocrine regulators of pituitary FSH. In this review we focus our attention on more recent developments in inhibin research. We describe patterns of inhibin A and B secretion during the estrous cycle. We also review the immunization against inhibin α subunit as a practical method for superovulation. Superovulation has been induced successfully by passive or active immunization against the inhibin α‐subunit in several species such as mice, rats, hamsters, guinea pigs, cows, mares, ewes and goats. Furthermore, several studies have shown that oocytes superovulated with immunization against inhibin α‐subunit have the ability to develop normally, suggesting that inhibin immunization could be used as a practical method for superovulation in a wide range of animal species.     

Immunolocalization of inhibin/activin subunits in the shiba goat fetal, neonatal, and adult testes

The objective of this study was to investigate the cellular immunolocalization of inhibin alpha and inhibin/activin (betaA and betaB) subunits in the fetal, neonatal and adult testes of Shiba goats. The testes were obtained from a fetus at 90 days, a neonate at 15 days, and two adult Shiba goats (both of 3 years old). The sections of testes were immunostained by the avidin-biotin-peroxidase complex method (ABC) using polyclonal antisera raised against porcine inhibin alpha, inhibin/activin betaA, and inhibin/activin betaB. Inhibin alpha and inhibin/activin (betaA and betaB) subunits were expressed in Leydig cells, but not in the Sertoli cells of the fetus with a weak immunostaining. An increase in the number of positive cells and a more intense immunohistochemical signal for inhibin alpha and inhibin/activin (betaA and betaB) subunits were observed in the Leydig cells of neonatal testes. Moreover, inhibin alpha, betaA, and betaB subunits were expressed in the Sertoli cells and Leydig cells of adult testes, respectively. These results suggest that Shiba goats testes have the ability to synthesize inhibins in the fetus, neonate, and adult, and the cellular localization of inhibin/activin subunits showed age-related changes in fetal, neonatal, and adult testes of Shiba goats.