皖西白鹅与朗德鹅垂体中GH基因表达的研究

本试验旨在研究生长激素对皖西白鹅与朗德鹅相关生长性能的影响。选择90日龄的皖西白鹅和朗德鹅各20只，于屠宰后称量每只鹅的屠体重，并将垂体组织在存入液氮后，采用半定量逆转录多聚酶链式反应（RT-PCR）的方法，以B—actin为内参，对其组织中GHmRNA表达量进行比较分析，并分别对两种鹅的屠体重进行相关性分析。结果表明：朗德鹅与皖西白鹅的屠体重（3029．25±269．455 vs 2920．313±457．604）差异不显著，并且公母之间均无显著差异。朗德鹅垂体中GHmRNA表达显著高于皖西白鹅（1．188±0．172 vs 0．744±0．289，p〈0．05），屠体重与GH mRNA的表达无显著相关。试验提示：GH mRNA表达量与两种鹅生长性能无明显关系，鹅的生长主要取决于生长激素的靶机制。     

短期饲喂二甲酸钾对断奶仔猪生长及其相关功能基因表达的影响

旨在探讨二甲酸钾(KDF)对断奶仔猪生长轴和肝脏糖异生相关基因mRNA表达的影响。试验选用28日龄的断奶仔猪180头,随机分为2组,每组6个重复,每个重复15头,其中对照组饲喂基础日粮,试验组饲喂基础日粮+1%的二甲酸钾,试验期2周。结果表明:与对照组相比,二甲酸钾显著提高断奶仔猪的平均日增重(P0.05),对血清中高密度脂蛋白胆固醇(HDL)、低密度脂蛋白胆固醇(LDL)、总胆固醇(TC)、甘油三酯(TG)和血糖(BG)等生化指标没有显著影响,对下丘脑中生长抑素(SS)、生长激素受体(GHR)、促生长激素释放激素(GHRH)和垂体中胰岛素样生长因子-1受体(IGF-1R)和生长激素(GH)mRNA表达量无显著影响。但试验组显著下调垂体中GHR的表达(P0.05),显著上调下丘脑中IGF-1R、肝脏中胰岛素样生长因子(IGF-1)、IGF-1R、磷酸稀醇式丙酮酸羧激酶(PCK1)和果糖-1,6-二磷酸酶(FBP1)mRNA的表达(P0.05)。     

生长激素和胰岛素样生长因子Ⅰ对奶牛乳蛋白合成关键激酶及调节因子mRNA表达量的影响

本试验旨在探讨生长激素(GH)和胰岛素样生长因子Ⅰ(IGF-Ⅰ)对体外培养的奶牛乳腺上皮细胞内调控乳蛋白合成的关键激酶及调节因子mRNA表达量的影响。试验对纯化后的荷斯坦奶牛乳腺上皮细胞进行4种处理,对照组采用无血清生长培养基,试验组在对照组的基础上分别添加GH(100 ng/mL)、IGF-Ⅰ(100 ng/mL)和GH(100 ng/mL)+IGF-Ⅰ(100 ng/mL)。培养24 h后,采用实时定量PCR(RT-qPCR)法测定κ-酪蛋白基因以及调控乳蛋白合成的关键激酶及调节因子的mRNA表达量,并测定生长激素受体(GHR)和胰岛素样生长因子Ⅰ受体(IGF-ⅠR)mRNA表达量。结果表明:体外培养的奶牛乳腺上皮细胞可以表达GHR和IGF-ⅠRmRNA,各试验组均能显著提高κ-酪蛋白(CSN3)mRNA表达量(P<0.05),但未发现GH和IGF-Ⅰ复合存在累积效应;与对照组相比,GH组有提高E74-样转录因子5(ELF5)mRNA表达量的趋势(P<0.10),而IGF-Ⅰ组显著提高了哺乳动物雷帕霉素靶蛋白(mTOR)和核糖体蛋白S6激酶1(rpS6K1)mRNA表达量(P<0.05),GH+IGF-Ⅰ组未呈现加强作用。结果提示,GH和IGF-Ⅰ可能单独通过影响调控乳蛋白合成的关键激酶及调节因子mRNA表达来调节κ-酪蛋白的合成。     

Ghrelin对莎能奶山羊下丘脑GHRH和SS mRNA表达的调节

为探讨ghrelin对奶山羊下丘脑促生长激素释放激素(GHRH)、生长抑素(SS) mRNA表达的影响,10只青春前期莎能母奶山羊随机分为2组,试验组和对照组,每组5只.试验组羊经颈静脉注入一定量的ghrelin(3.0 μg/kg)3 h后宰杀,用RT-PCR方法检测ghrelin对下丘脑GHRH、SS mRNA表达的影响.结果表明试验组羊下丘脑GHRH mRNA的表达显著上调(P＜0.01);下丘脑中SS mRNA的表达也显著升高(P＜0.05).表明ghrelin在下丘脑水平上对GHRH和SS mRNA的表达具有上调作用,提示ghrelin可能通过GHRH途径调节垂体GH的分泌.     

皖西白鹅与朗德鹅脂肪基因表达的比较

选择90日龄的皖西白鹅和朗德鹅各20只,取其腹腔脂肪,用半定量逆转录多聚酶链式反应(RT-PCR)的方法,以β-actin为内标,比较分析腹脂中的脂联素(adiponectin,ADP)、脂联素-2型受体(adiponectin receptor 2,ADPR2)、瘦素(leptin, LEP )mRNA的表达,并与腹脂重进行相关性分析,采用ELISA方法测定两种鹅血液中ADP水平.结果表明:皖西白鹅的腹脂重和腹脂率与朗德鹅无显著差异;皖西白鹅腹脂ADP mRNA的表达显著高于朗德鹅(P<0.05),而ADPR2显著低于朗德鹅(P<0.05),LEP mRNA表达在两品种间无显著差异;腹脂重与ADP、AdipoR2、LEP mRNA的表达无显著的相关性;皖西白鹅血液中脂联素含量显著低于朗德鹅(P<0.05).结果提示:①鹅腹脂中ADP及其受体的基因表达存在品种差异;②鹅腹脂分泌的ADP可能不是血液中ADP的主要来源.     

济宁青山羊生后乳腺GHR和IGF-ⅠR的分布及其mRNA表达的发育性变化

采用SABC法检测济宁青山羊生后发育过程中生长激素受体(growth hormone receptor,GHR)与胰岛素样生长因子Ⅰ受体(insulin like growth factorⅠreceptor,IGF-ⅠR)在乳腺组织中的分布;GAPDH作为内参基因,qRT-PCR法检测GHR mRNA与IGF-ⅠR mRNA相对表达量。结果显示:GHR和IGF-ⅠR阳性物质主要在乳腺组织内的导管上皮细胞、基质细胞和血管内皮细胞的胞质中表达,细胞核偶有表达;GHR和IGF-ⅠR阳性细胞光密度值与其mRNA表达趋势基本一致,但IGF-ⅠR的表达量低于GHR;GHR和IGF-ⅠR在出生当天表达水平较低,60日龄(初情期)和120日龄(性成熟)出现峰值(P0.05),120日龄后逐渐下降。结果表明:济宁青山羊生后发育时期,GHR与IGF-ⅠR对乳腺的生长发育具有重要的调节作用,初情期和性成熟期可能是乳腺生长发育最快的阶段。     

动物GH/IGF-Ⅰ轴调控机制的研究进展

生长轴是动物体内下丘脑－垂体－靶器官一系列激素及其受体所组成的神经内分泌系统。通过提高生长轴中生长激素(GH)和胰岛素样生长因子-Ⅰ(IGF-Ⅰ)水平,促进增重、提高饲料转化率和改善肉品质,是畜禽生长调控的一种新途径。GH通过IGF-Ⅰ介导调节动物生长和细胞分化等,文章综述了GH/IGF-Ⅰ轴的组成、功能,以及GH调控IGF-Ⅰ表达的分子机理。     

太湖鹅与皖西白鹅胸肌IGF-I和MSTN的表达及其与屠宰性状相关性分析

本研究旨在探讨IGF-I、MSTN对鹅骨骼肌生长的影响。以太湖鹅和皖西白鹅为研究素材,采用多重荧光竞争性PCR和酶联免疫方法,测定鹅70日龄胸肌中IGF-I、MSTN的mRNA和蛋白表达情况,并与屠宰性能做相关性分析。结果证实,70日龄时太湖鹅体重、胸肌重极显著小于皖西白鹅,但是胸肌率没有差异,并且品种间在体重和胸肌重上存在性别差异;胸肌IGF-I和MSTN的mRNA、蛋白表达均无品种差异,并且在品种间也不存在性别差异;同一品种的公母鹅相比较,太湖鹅公鹅胸肌IGF-I mRNA表达显著高于母鹅;除了胸肌IGF-I的含量与MSTN的mRNA表达和蛋白含量呈显著正相关,胸肌IGF-I、MSTN的mRNA表达和蛋白含量相互之间均无显著相关性,鹅胸肌IGF-I mRNA表达量和胸肌率、胸肌重、体重呈显著负相关,皖西白鹅胸肌中MSTN的表达与体重呈强的负相关。结果提示,70日龄时鹅胸肌生长正负调节基因IGF-I与MSTN的表达无品种特异性,二者表达水平处于一个动态平衡之中,特别参与了70日龄皖西白鹅的生长调控。     

中国美利奴绵羊肉用品系生长轴相关基因表达对其十二指肠发育的影响

本文旨在探讨生长轴基因与羔羊十二指肠生长发育的关系。分别于0、7、14、30、60和90日龄随机选取健康的中国美利奴绵羊(新疆军垦型)肉用品系雌、雄各3只,测定体质量后屠宰,迅速采集其脑垂体、肝脏和十二指肠等组织样品,并测量十二指肠长度。用荧光实时定量PCR法分别测定脑垂体中生长激素(GH)和生长激素释放激素受体(GHRHR),肝脏和十二指肠中生长激素受体(GHR)、胰岛素样生长因子1(IGF-1)和胰岛素样生长因子1受体(IGF-1R)基因表达的发育性变化,并进行了性别间比较。结果表明,羔羊肝脏中GHR基因和十二指肠中GHR、IGF-1基因表达mRNA丰度的变化模式与垂体中GH和GHRHR基因表达mRNA丰度的变化发育模式相似,呈先升高后逐渐下降的趋势,但这种趋势有一定的时差性;十二指肠的日增长发育性变化模式与肝脏中IGF-1基因表达的变化模式相似。结果提示,十二指肠的发育性变化主要受到肝脏中产生的IGF-1内分泌作用的调控,同时也可能受到脑垂体中GH内分泌的直接作用。     

畜禽生长激素受体基因的研究进展

生长激素受体（GHR）是一种跨膜糖蛋白,GHR可以与脑垂体产生的生长激素（GH）相结合,启动细胞内的信号转导机制,增加胰岛素样生长因子-1(IGF-1)的表达,促进细胞增殖,最终发挥调控动物骨骼肌生长发育的作用。本文综述了GHR基因的功能与结构、GHR基因在羊、牛、猪、家禽及其他动物中的最新研究进展，为更深入研究GHR基因对动物生产性能的影响提供参考。     

生长激素促进细胞增殖机理的研究进展

生长激素(growth hormone,GH)对动物的生长发育具有重要的作用,其直接或间接通过诱导胰岛素样生长因子1(insulin-like growth factor 1,IGF-1)促进干细胞的活化、细胞增殖和分化,并通过细胞膜受体发挥作用启动一系列信号通路.文章就生长激素对细胞增长的作用和功能进行简要概述.     

激素调控促进动物生长发育的研究

激素对机体的代谢、生长、发育、繁殖、性别、性欲和性活动等起重要的调节作用。动物机体通过各种内分泌腺分泌的激素,间接调节动物机体的活动。内分泌腺分泌的激素直接进入血液、随着血液循环到达身体各个部分,在一定的器官或组织中发生作用,从而协调动物机体新陈代谢、生长、发育、生殖及其它生理机能,使这些机能得到兴奋或抑制,使它们的活动加快或减慢。生长激素可以促进蛋白质的合成与骨的生长,甲状腺激素促进新陈代谢和生长发育,可以提高神经系统的兴奋。胰岛分泌的激素可以控制糖类代谢,调节血糖含量。性激素促进生殖器官的生长发育,维持第二性征。     

The effect of lighting conditions on the rhythmicity of growth hormone secretion in Holstein steers

Growth hormone (GH) secretion regularity and the effects of lighting condition and GH‐releasing hormone (GHRH) on GH release were determined in steers. First, steers were kept under 12:12 L : D conditions (light: 06.00–18.00 hours). The animals were then subjected to a 1‐h advancement in lighting on/off conditions (05.00 and 17.00 hours, respectively). Blood was sampled for 24 h at 1‐h interval on the seventh day of each condition. Second, GHRH was injected intravenously (IV) at 12.00 and 00.00 hours under 12:12 L : D and blood was sampled at 15‐min interval for 4‐h (1 h before and 3 h after the injection). Plasma GH concentrations were measured by a radioimmunoassay. Periodicity of GH secretory profile was calculated by power spectrum analysis using the maximum entropy method. Plasma GH concentrations showed a characteristic pattern consisting of four distinct peaks. Mean periodicity of GH secretory profile was 5.7 h, and it was not altered by any change in lighting conditions. IV injection of GHRH increased GH secretion during the day and night. The increase in GH secretory volume after GHRH injection during the night was equal to that during the day. The present results suggest that GH secreted from the anterior pituitary have regularity in steers.     

玉米赤霉烯酮对青年母猪子宫发育、生长激素分泌及其受体分布与表达的影响

本试验旨在研究玉米赤霉烯酮(ZEA)对青年母猪子宫发育、生长激素(GH)分泌及其受体(GHR)分布与表达的影响.选择胎次和体重[(23.20±0.68)kg]相近的长×大二元青年母猪48头,将其随机分为4组,每组12个重复,每个重复1头.对照组(CON组)饲喂基础饲粮,试验组(T1、T2、T3组)饲喂在基础饲粮中分别添...     

生长激素激活受体机理的研究进展

生长激素(growth hormone,GH)是一种含有191个氨基酸的多肽类激素,分子质量为22 ku,由垂体前叶分泌进入血液循环,与靶细胞膜表面以二聚体形式存在的生长激素受体(growth hormone receptor,GHR)相结合。对于受体的激活来说,仅是二聚化还不够,还需在GH的诱导下发生构象变化,进而才能诱发Janus激酶2(Janus kinase 2,JAK2)的酪氨酸磷酸化,并通过4条不同的路径将信号传入细胞内,从而发挥代谢、增殖及分化等一系列生理效应。作者就生长激素与受体的结构、作用机理、信号转导通路的进展进行综述。     

Effect of Kisspeptin on Regulation of Growth Hormone and Luteinizing Hormone in Lactating Dairy Cows

Kisspeptin (KP),a neuroendocrine regulator of reproduction,is hypothesized to be an integrator of metabolism and hormones critical to the regulation of reproduction.Lactation is associated with enhanced growth hormone (GH) responsiveness and reduced fertility.Our study was designed to determine the effects of lactation on KP-stimulated GH and luteinizing hormone (LH) secretion.Five nonlactating and five lactating dairy cows were used in the study.Experiments were conducted with lactating cows at weeks 1,5 and 11 after parturition.The experimental treatments (saline and KP [ 100 and 400 pmol/kg body weight] ) were given intravenously and blood was collected and plasma was stored until later assay to determine concentrations of GH,LH,progesterone and non-esterified fatty acids.We found that neither dose of KP stimulated an increase in GH secretion.The low dose of KP increased (P ＜0.05)LH concentrations only in lactating cows.The higher dose of KP elicited an increase in circulating LH concentrations in both lactating and non-lactating cows.The lower dose of KP increased ( P ＜ 0.05 ) the area under the curve for LH only in cows during week 5 of lactation,and the area under the curve of LH following the highest dose of KP was greater ( P ＜ 0.05 ) in cows during week 5 of lactation than that for the other groups of cows.In summary,lactation status and stage of lactation did not change the sensitivity of the GH system to KP.However,an effect of stage of lactation on KP-stimulated LH secretion was detected in the dairy cows.Study of the KP system during lactation in dairy cows may provide critical insights into the mechanisms for lactation-associated changes in the reproductive axis.     

绍鸭生长的内分泌机理

通过测定与有关的激素研究了绍鸭生长的内分泌机理。生长期生长激素（ＧＨ）的最大值出现在３５日龄,整个生长期ＧＨ的变化模式是先升后降。血浆生长抑素（ＳＳ）的最大值出现在３日龄,整个生长期ＳＳ的变化模式是先降后升。ＧＨ和ＳＳ的变化有很强的负相关（r＝０．８１８３）。公母绍鸭生长期三碘甲状腺原氨酸（Ｔ３）、甲状腺素（Ｔ４）水平 的变化模式基本相同。整个生长期,Ｔ３水平先降后升,生长早期（１５～３５日龄）血浆     

Growth hormone receptor (GHR) RNAi decreases proliferation and enhances apoptosis in CMT-U27 canine mammary carcinoma cell line

Canine mammary gland has been identified as a major site of the extrapituitary growth hormone (GH) production. This finding is linked to its role in tumourigenesis of the mammary gland. Our previous studies indicated the role of GH and GH receptor (GHR) in regulation of proliferation and apoptosis. Thus, we have optimized the ghr RNA interference method in canine mammary carcinoma cell line CMT-U27. We have analysed the effect of GHR reduction on the intracellular signalling and the cell cycle and apoptosis. The results showed that GHR reduction decreased the p-ERK1/2 expression and caused increase of apoptosis and decrease in number of cells at S and G2M phases. This study indicates that GHR besides proliferative effect promotes growth by increasing cell survival. It can tilt the balance between proliferation and death in cancer cells.     

Evaluation of the safety of daily administration of capromorelin in cats

Capromorelin is a ghrelin receptor agonist that is FDA approved for appetite stimulation in dogs. The objective of this study was to evaluate the safety of daily oral administration of capromorelin to cats over a range of doses and for an extended period. Two randomized, controlled studies were conducted: in Study 1, cats (n = 6 per group) received placebo or capromorelin at a dose of 9, 15, 30 or 60 mg/kg once daily for 14 days; and in Study 2, cats received capromorelin at 6 mg/kg (n = 8) or placebo (n = 4) once daily for 91 days. Cats were evaluated using clinical observations and clinical pathology test results for both studies, with the addition of postmortem examination in Study 1 and measurements of growth hormone and insulin‐like growth factor 1 in Study 2. Abnormal clinical observations were limited to emesis, hypersalivation, lethargy/depression, head shaking and lip smacking, which occurred more frequently in the capromorelin‐treated groups than in the placebo group. There were no clinically relevant differences in clinical pathology test results between the capromorelin and placebo groups in either study.     

鸡生长激素受体胞外区原核表达分析

生长激素与其靶细胞膜表面的生长激素受体(GHR)结合,可以促进动物生长发育和调节新陈代谢。为获得鸡GHR蛋白,试验通过PCR扩增获得GHR胞外区序列。经双酶切后连接入原核p ET-32a(+)表达载体,构建了鸡GHR胞外结构域的原核表达载体。将该重组质粒转入E. coli BL21(ED3)表达菌株。通过IPTG诱导其表达GHR重组蛋白,并探讨不同IPTG浓度、诱导时间和诱导温度等条件对鸡GHR重组蛋白表达的影响。结果表明:诱导GHR重组蛋白表达的最适条件为IPTG终浓度2.00 mmol/L、诱导时间为4 h、培养温度为37℃,在此条件下,GHR重组蛋白表达量最高。研究结果为后续GHR抗体制备奠定了基础。