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-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...     

脂联素及其受体的研究进展及在生殖中的作用

脂联素是一种由脂肪组织分泌的具有多种生物学功能的特殊蛋白,在增强脂肪酸氧化、抗炎症反应、抗糖尿病等方面起重要作用。脂联素通过AdipoR1和AdipoR2这两种受体的介导经过AMPK、PPAR、p38MAPK等信号通路来发挥生物学作用。脂联素及其受体AdipoR1和AdipoR2能在多种组织器官中表达,AdipoR1主要在肌肉组织中表达,AdipoR2则高表达于肝脏组织。此外,脂联素及其受体还能在下丘脑、垂体、子宫、胚胎等多种生殖腺和生殖组织中表达,说明脂联素在调控动物生殖及胚胎生长发育方面起重要作用。     

抑制素对动物生殖的调控作用

抑制素具有抑制垂体分泌FSH的作用,文章主要综述抑制素对雄性动物生殖和雌性动物生殖作用。     

β胡萝卜素对母牛生机能的作用

<正> 大量试验证明、当用青绿料青贮或加工干草时、葫萝卜素的损耗平均为29％、同时、牛对葫萝卜素的吸收率也较低、固而常招致其生殖机能失调、即使补加维生素A来弥补也无济于事,唯一的办法就是在牛的日粮中补加人工合成或微生物合成的β葫萝卜素才能使其生殖机能维持正常。为证实微生物合成的β葫萝卜素对初胎母牛生殖机能的作用、畜牧工作者伊·格·匹辅纳     

增食欲素及其生理功能研究进展

<正>近几年,在下丘脑发现了可促进食欲且来源于同一前体的两种新神经肽:增食欲素A和B(orexinA和B),它们可激活两种密切相关且与G蛋白偶联的细胞表面受体(GPCRs)。研究显示它在增加摄食、饮水,调节睡眠觉醒周期、生殖、体温、血压和感觉等方面有广泛作用。本文综述了增食欲素的基因及蛋白质结构、组织分布和功能,以及增食欲素受体,探讨了增食欲素的作用机理,并对其在动物生产中的应用前景作了展望。     

TGF-β通路与哺乳动物卵母细胞发育研究进展

转化生长因子β(TGF-β)信号通路是一个包含众多成员的多功能细胞因子的大家族,其在卵母细胞形成和发育方面发挥重要的作用。TGF-β信号通路主要是通过配体与受体结合形成复合物,从而激活相关分子调控关键基因的表达。这一系列过程包括直接参与调控作用的骨形成蛋白(BMPs)、激活素(activins)、抑制素(inhibin)、TGF-β和抗苗勒管素(AMH)。另外,还通过偶联环腺苷酸(cAMP)、激素和表皮生长因子(EGF)三个主要途径间接影响TGF-β通路对卵母细胞的发育。论文通过综述TGF-β通路对哺乳动物卵母细胞发育影响的研究进展,为相关研究提供参考。     

脂联素与其受体的结构及在脂类代谢中的作用机制

脂联素（AdipoQ）是一种主要由脂肪组织分泌的内源性细胞因子,在调节脂类代谢中发挥重要作用。AdipoQ首先与其受体[脂联素受体1(AdipoRl)和脂联素受体2(AdipoR2)]位于膜外的C端结合,再通过AdipoQ受体N端与信号接头蛋白结合,进而激活下游腺苷酸活化蛋白激酶（AMPK）与过氧化物酶体增殖物激活受体α(PPARα)等多条信号通路,促进脂肪酸氧化,抑制脂质合成,从而调节脂类代谢。本文就AdipoQ及其受体的结构、信号接头蛋白和AdipoQ对动物脂质代谢的调节机制进行综述。     

激活素A调控促卵泡素合成与分泌的研究进展

垂体促卵泡素(follicle-stimulating hormone, FSH)具有调节配子发生、类固醇激素生成、细胞代谢等功能，在哺乳动物的繁殖活动中起着十分重要的作用。作为转化因子-β超家族(TGF-β superfamily)成员之一，激活素A(Activin A)能够选择性促进FSH的合成与分泌。文章就激活素A的生物学功能与其调控FSH合成与分泌的最新研究进展进行了梳理与总结，为进一步深入探索激活素A的功能及开发动物繁殖人工调控相关激素制品提供理论参考与依据。     

脂联素及其受体在动物下丘脑-垂体-性腺轴中的表达与作用

下丘脑-垂体-性腺(HPG)轴在动物生殖调控中扮演重要角色,研究HPG轴功能的调控因子及机制已成为生殖内分泌学领域的热点。近年来的研究发现,脂肪组织能合成和分泌多种细胞因子,其中脂联素及其受体在调控动物生殖及胚胎生长发育方面起到重要作用,本文就脂联素及其受体在动物HPG轴的表达与作用进行综述。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Mechanism of Action of Probiotic Function of Lactobacilli

乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.