促性腺激素抑制激素研究进展

<正>促性腺激素抑制激素(GnIH),这种神经肽最初在鹌鹑被发现,无论是体内还是体外都抑制垂体促性腺激素的释放。这种影响随后也被证实,对啮齿目动物和绵羊使用鸟类GnIH和哺乳动物类似肽也抑制垂体促性腺激素的释放。另外,GnIH还抑制垂体促性腺激素共同的α亚基和特有的β亚基的合成。所以,对垂体前叶GnIH及其作用的研究的确证     

促性腺激素峰抑制因子

从70年代到80年代初,人们证明了卵巢卵泡液中存在有生物活性的抑制素,其来源是颗粒细胞。大多数研究表明,抑制素主要在垂体水平上选择性地抑制促卵泡素(FSH)的释放;少数报道抑制素对促黄体素(LH)分泌也有抑制作用。到80年代中期,从牛和猪卵泡液中提纯了抑制素,并克隆出了其互补 DNA,确定了这种分子的结构,并在此基础上建立了该激素的特异性放射免疫测定方法,从而使有关抑制素的研究更加深入。     

哺乳动物促性腺激素细胞研究进展

哺乳动物促性腺激素细胞的增殖分化受多种因子影响,它分泌的促性腺激素在生殖调控中占有中心地位。文章系统地介绍了促性腺激素细胞的组织胚胎学研究、促性腺激素细胞分泌的促卵泡素和促黄体素的基因表达调控、分泌调节和合成代谢的研究情况,为研究生殖内分泌提供系统的资料。     

促性腺激素释放激素基因及其受体基因的研究进展

作者简要介绍了促性腺激素释放激素基因及其受体基因的位置、结构、表达、调控机理,并初步探讨了这两个基因与繁殖性能的关系。     

促性腺激素抑制激素对SD大鼠性腺生殖功能与糖代谢的影响

【目的】 探究促性腺激素抑制激素（GnIH）对SD大鼠性腺生殖功能和糖代谢的影响,以及SD大鼠性腺生殖功能和糖代谢之间的相关性。【方法】 将36只SD大鼠随机均分为对照组（0.9％生理盐水）、1 μg/100 μL GnIH组（Ⅰ组）、10 μg/100 μL GnIH （Ⅱ组）,每组12只（雌雄各半）。每天07：00和19：00注射生理盐水或GnIH （200 μL/次）,连续注射14 d后测量大鼠体重,计算肥胖程度,麻醉处死后采集卵巢和睾丸,称重并计算卵体比和睾体比;运用阴道涂片法观察雌性大鼠发情周期的变化;显微镜下观察并计算雄性大鼠精子活力;HE染色观察卵巢和睾丸组织变化;用实时荧光定量PCR法检测卵巢和睾丸中糖代谢基因胰岛素受体（IR）、葡萄糖转运蛋白4（GLUT4）和炎症相关因子肿瘤坏死因子（TNF-α）、白介素1β（IL-1β）的表达水平,并用SPSS 22.0软件分析生殖功能和糖代谢之间的相关性。【结果】 与对照组相比,Ⅰ组雌性SD大鼠和Ⅱ组雄性SD大鼠肥胖程度均显著升高（P<0.05）;Ⅱ组卵巢大小/重量、卵体比显著升高,睾丸重量、睾体比显著下降（P<0.05）。HE染色结果显示,与对照组相比,Ⅱ组雌性大鼠卵泡呈囊性扩张,颗粒细胞层减少,卵泡腔变大;Ⅰ、Ⅱ组雄性大鼠的生精小管均出现空泡样改变,生精细胞排列紊乱、层次减少。与对照组相比,Ⅱ组大鼠发情前期的持续时间显著延长（P<0.05）、精子活力显著下降（P<0.05）。实时荧光定量PCR结果显示,与对照组相比,Ⅰ、Ⅱ组雌性大鼠GLUT4基因的表达量极显著下降（P<0.01）、Ⅱ组中IR基因的表达量显著降低（P<0.05）,Ⅰ、Ⅱ组雄性大鼠GLUT4基因的表达量均极显著降低（P<0.01）;Ⅰ组雌性大鼠TNF-α、IL-1β基因和雄性大鼠IL-1β基因的表达量均显著升高（P<0.05）,Ⅱ组雌、雄大鼠TNF-α基因的表达量均极显著升高（P<0.01）。相关性分析结果显示,腹腔注射GnIH后,雌性大鼠的卵体比与GLUT4基因表达水平呈极显著正相关（P<0.01）,与IR基因的表达水平呈显著正相关（P<0.05）;雌性大鼠的发情周期与GLUT4基因表达水平呈极显著负相关（P<0.01）;雄性大鼠睾体比与GLUT4基因表达水平均呈显著正相关（P<0.05）,而精子活力与GLUT4基因表达水平均呈极显著正相关（P<0.01）。【结论】 腹腔注射GnIH能够抑制大鼠的生殖功能和导致糖代谢功能紊乱,而且GnIH可能参与性腺能量代谢与生殖功能的交叉对话,是能量代谢与生殖功能的新型联络因子。     

促性腺激素对牛超数排卵的研究进展

使用促性腺激素对牛进行超数排卵处理时产生的不同效果,是超数排卵(简称超排)反应出现个体差异性的主要原因之一。文章就牛胚胎移植研究和生产应用中使用不同的促性腺激素及其使用方法的研究进行综述,以提供简化有效的使用激素超排的方法,为牛的超排和胚胎移植提供有价值的参考。     

促性腺激素细胞的研究进展

哺乳类和鱼类的促性腺激素(GTH)细胞都是位于腺垂体,所分泌的激素有促卵泡激素(FSH)和促黄体素(LH),促卵泡激素可以促成卵细胞和精子的生成,而促黄体素可以促进孕酮和睾酮的产生,关于促性腺激素细胞的来源有三种假说,在所有的对促性腺激素细胞调节控制的因素中,最重要的是促性腺激素释放激素(GnRH)。文章从促性腺激素细胞的定位、功能、源泉细胞,以及对其调节控制等方面的研究进展作一综述,以期为在实践中加强对动物生殖规律的人工调控提供参考。     

促性腺激素抑制激素基因疫苗pVAX-RFRP和抑制素基因疫苗pXAIS对水牛卵泡发育的影响

40头奶水牛分4组,每组10头。Ⅰ组:p VAX-RFRP质粒肌注+p XAIS质粒肌注+p XAIS活菌苗喷鼻;Ⅱ组:p XAIS质粒肌注+p XAIS活菌苗喷鼻;Ⅲ组:p VAX-RFRP质粒肌注;Ⅳ组:PBS肌注对照。研究抑制素基因疫苗(p XAIS)和促性腺激素抑制激素基因疫苗(p VAX-RFRP)对水牛发情和卵泡发育的影响。结果表明:Ⅰ组和Ⅲ组水牛很快发情,与Ⅳ组(PBS对照)差异显著(P0.05),Ⅱ组与Ⅳ组(PBS对照)差异不显著,3个试验组之间差异不显著。3个试验组总卵泡数都比对照组多(P0.05),Ⅱ组大卵泡数较多,与Ⅳ组(PBS对照)差异显著(P0.05),各试验组间大卵泡数不存在显著差异。结果表明,两种疫苗都显著促进水牛发情,并有利于大卵泡发育。     

促性腺激素释放激素的研究进展

促性腺激素释放激素 (ＧｎＲＨ) ,又称黄体生成素释放激素(ＬＨＲＨ) ,为下丘脑神经元分泌的十肽激素 ,其化学结构为 :(焦 )谷 -组 -色 -丝 -落 -甘 -亮 -精 -脯 -甘 -ＮＨ2 。迄今还未发现哺乳类动物ＧｎＲＨ的结构有什么不同。下丘脑分泌的ＧｎＲＨ由垂体门脉系统到达垂体前叶 ,作用于垂体前叶的促性腺激素细胞 ,膜上的ＧｎＲＨ受体 ,通过磷脂酰肌醇系导细胞内钙离子浓度增加 ,促进垂体前叶分泌促卵泡素 (ＦＳＨ)和黄体生成素 (ＬＨ)。ＦＳＨ促进卵巢的卵泡生长发育 ,而在ＦＳＨ和ＬＨ共同作用下 ,使成熟的卵泡分泌雌激素和孕激素。下丘脑…     

性腺外FSH受体和LH受体表达研究进展

雌性动物的性腺是卵巢,性腺外的生殖组织器官主要包括:输卵管、子宫颈、子宫肌层等,其中子宫是内分泌器官,除有局部内分泌功能外,还可能对下丘脑-垂体-卵巢轴有调节作用.促卵泡素(FSH)和促黄体素(LH)的生理功能是通过其FSHR、LHR来介导的,其受体在性腺和性腺外均有表达.本文主要对雌性性腺外生殖组织器官上两种受体的表达加以综述.     

类固醇激素受体与中性粒细胞功能的研究进展

"免疫抑制"一直是临床医学上关注的焦点,而内源性的雌激素、孕酮和糖皮质激素等主要的类固醇激素水平的剧烈变化被认为是导致PMN等免疫细胞功能障碍,进而诱发免疫抑制的原因。本文就类固醇激素受体介导类固醇激素对中性粒细胞功能影响的分子机制进行综述。     

Advances in echocardiography

Before the development of echocardiography, cardiac disease in the horse was diagnosed if a loud heart murmur (grade III-IV/VI or louder) and clinical signs of congestive heart failure (coughing, edema, venous distention, jugular pulsations) were detected on physical examination. Arrhythmias that persisted during and after exercise also indicated cardiac disease, which could be characterized electrocardiographically. Electrocardiography, thoracic radiography, angiography, cardiac catheterization, and oximetry could add only small pieces of information about the heart. M-mode echocardiography provided the first "window" with which to evaluate the heart and its intracardiac structures, albeit an ice-pick one-dimensional view. With M-mode echocardiography, the diameter of the aorta at the valves, the left ventricle, right ventricle, and left atrial appendage, as well as the thickness of the interventricular septum and left ventricular free wall, could be measured. Motion and thickness of the tricuspid, mitral, and aortic valves could be assessed, but only in a one-dimensional plane. Two-dimensional echocardiography provided an added dimension, resulting in visualization of all the intracardiac structures, aorta, and pulmonary artery. Two-dimensional echocardiography became the diagnostic technique of choice for the evaluation and characterization of congenital cardiac disease in critically ill neonates, as well as in adult horses. Two-dimensional echocardiography also improved the ability to diagnose valvular regurgitations, characterize valvular lesions (bacterial endocarditis, ruptured chorda tendineae), myocardial function (segmental wall motion abnormalities), atrial size, mass lesions (endocarditis, neoplasia, and thrombi), and pericardial effusion. Information about blood flow was obtained using contrast echocardiography but was limited to certain cardiac abnormalities (congenital cardiac defects and tricuspid regurgitation). This information about blood flow was limited to the detection of positive or negative contrast jets. Comprehensive information about blood flow was lacking until the application of Doppler echocardiography to equine cardiology. Pulsed-wave and color flow Doppler echocardiography resulted in precise localization of the abnormal blood flow and semiquantitation of the shunt flow or regurgitant jet. Color flow Doppler echocardiography sped up the localization and semiquantitation of the jet in many instances and provided some information about blood flow velocity in the enhanced and variance modes. The peak velocity of jets can be determined using continuous-wave Doppler echocardiography. This value then can be used to estimate pressure difference between cardiac chambers or to calculate cardiac output noninvasively if angles parallel to flow can be obtained. Thus, information about cardiac size, function, and blood flow can be combined to diagnose cardiac disease in horses and to formulate a prognosis for life and performance.     

Advances in immunoparasitology

A selective review of the advances in immunoparasitology is presented. It is selective simply because it is not feasible to embrace the whole field of parasitology within the compass of a single review paper, for if it were attempted, it would suffer undue abbreviation. Emphasis is placed on the advances in helminthology and especially the gastro-intestinal parasites of ruminants, an obvious selection because of the interests of the author. Reviews are always somewhat retrospective in outlook; to write a review at the present time is especially foolhardy since developments in biology are such that totally new concepts can arise almost overnight, as it were. This is a particularly healthy state, and the discipline of parasitology is caught up in the application and interpretation of molecular biological considerations. "Parasitism" is a field of increasing importance and challenge.     

Thyrotropin releasing hormone interactions with growth hormone secretion in horses

Light horse mares, stallions, and geldings were used to 1) extend our observations on the thyrotropin releasing hormone (TRH) inhibition of GH secretion in response to physiologic stimuli and 2) test the hypothesis that stimulation of endogenous TRH would decrease the normal rate of GH secretion. In Exp. 1 and 2, pretreatment of mares with TRH (10 microg/kg BW) decreased (P < 0.001) the GH response to exercise and aspartate infusion. Time analysis in Exp. 3 indicated that the TRH inhibition lasted at least 60 min but was absent by 120 min. Administration of a single injection of TRH to stallions in Exp. 4 increased (P < 0.001) prolactin concentrations as expected but had no effect (P > 0.10) on GH concentrations. Similarly, 11 hourly injections of TRH administered to geldings in Exp. 5 did not alter (P > 0.10) GH concentrations either during the injections or for the next 14 h. In Exp. 5, it was noted that the prolactin and thyroid-stimulating hormone responses to TRH were great (P < 0.001) for the first injection, but subsequent injections had little to no stimulatory effect. Thus, Exp. 6 was designed to determine whether the inhibitory effect of TRH also waned after multiple injections. Geldings pretreated with five hourly injections of TRH had an exercise-induced GH response identical to that of control geldings, indicating that the inhibitory effect was absent after five TRH injections. Retrospective analysis of pooled, selected data from Exp. 4, 5, and 6 indicated that endogenous GH concentrations were in fact lower (P < 0.01) from 45 to 75 min after TRH injection but not thereafter. In Exp. 7, 6-n-propyl-2-thiouracil was fed to stallions to reduce thyroid activity and hence thyroid hormone feedback, potentially increasing endogenous TRH secretion. Treated stallions had decreased (P < 0.01) concentrations of thyroxine and elevated (P < 0.01) concentrations of thyroid-stimulating hormone by d 52 of feeding, but plasma concentrations of GH and prolactin were unaffected (P > 0.10). In contrast, the GH response to aspartate and the prolactin response to sulpiride were greater (P < 0.05) in treated stallions than in controls. In summary, TRH inhibited exercise- and aspartate-induced GH secretion. The duration of the inhibition was at least 1 h but less than 2 h, and it waned with multiple injections. There is likely a TRH inhibition of endogenous GH episodes as well. Reduced thyroid feedback on the hypothalamic-pituitary axis did not alter basal GH and prolactin secretion.