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1.
JAK-STAT信号通路是阐明细胞因子生物学功能及病毒如何发挥作用的分子基础，但对于猪圆环病毒2型（PCV2）感染及病毒复制的作用机制，目前尚无报道。本研究采用PCR列阵方法，建立PK-15细胞JAK-STAT信号通路的功能分类芯片，分析JAK-STAT信号通路中所有已知的Jak和Stat家族成员、激活JAK-STAT信号通路的受体，以及与Stat蛋白相关的核辅助因子及共同活化因子、Stat诱导蛋白及该通路的负反馈调节蛋白等基因在PCV2感染后的差异表达情况，为进一步明确PK-15细胞JAK-STAT信号通路对病毒复制力和复制机制奠定基础。 相似文献
2.
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。 相似文献
3.
《中国兽医学报》2015,(8):1302-1306
为探讨小G蛋白Ran对β-酪蛋白合成的主要信号通路mTOR和Jak2/Stat5及其增殖的影响,本研究对Ran进行瞬时转染和稳定转染,Western blot检测细胞中mTOR、p-mTOR、Stat5和p-Stat5的表达;高压液相层析仪检测酪蛋白的分泌量;CASY细胞活力分析仪分析细胞活力。结果显示,Ran过表达时,细胞活力显著增加(P0.01),细胞中mTOR、p-mTOR、Stat5和p-Stat5的表达均也显著增加(P0.01);表明Ran可能激活细胞中的mTOR通路和Jak2/Stat5通路,对乳腺上皮细胞的泌乳与增殖有正向调节作用。 相似文献
4.
生长激素和胰岛素样生长因子结合蛋白及其功能 总被引：2，自引：0，他引：2
生长激素和胰岛素样生长因子，如同甲状腺素和类固醇激素一样，也具有特异的结合蛋白。近来已从不同动物中发现了高亲和生长激素结合蛋白和四种胰岛素样生长因子结合蛋白。它们对地相应的激素功能的表达具有重要作用，对循环激素的储存，运输以及激素活性的维持等方面具有特异的调控作用。 相似文献
6.
猪生长激素基因的原核表达及其抗体制备 总被引：6，自引：0，他引：6
通过构建pGH基因的原核表达质粒，转化大肠埃希氏菌TOP10，经IPTG诱导，成功表达了重组猪生长激素的融合蛋白。经SDSPAGE分析，在分子质量50．4ku处有1条新的特异蛋白质条带。对以包涵体形式表达的融合蛋白进行SDSPAGE分离，并经透析得到了重组融合蛋白，以此融合蛋白免疫家兔，制备并纯化了抗pGH多克隆抗体，经酶联免疫吸附测定、蛋白质印迹分析和免疫组织化学方法检测，此抗体具有较高效价和特异性。成功地表达了pGH基因并获得了多克隆抗体。 相似文献
7.
生长激素对动物的生长发育具有重要作用。而肝脏是生长激素发挥生理作用的重要靶器官。生长激素在肝细胞上发挥生理作用的主要信号转导通路是JAK-STATs、ERK等。在饥饿应激条件下,生长激素的作用减弱,动物机体IGF-1的分泌量大大减少,但其减少的原因尚不清楚。本研究通过饥饿大鼠使其处于应激状态,在饥饿应激模型上研究生长激素对肝脏细胞一些主要信号通路的影响。将大鼠分为2组,一组为正常饲喂组(48h),另外一组为饥饿组(48h),通过门静脉注射重组人生长激素,在注射后的0和25min时进行离体肝脏灌流并分析胞内信号分子磷酸化水平的变化。结果显示,正常饲喂条件下,注射生长激素组鼠肝脏细胞的JAK2、STAT1/3/5、ERK1/2等胞内信号分子会发生明显磷酸化,但在饥饿组,只能观察到肝细胞JAK2和STAT1/3/5微弱的磷酸化,ERK1/2磷酸化程度没有变化。此外,饥饿并没有改变细胞内蛋白总量和肝脏细胞表面受体的数量。因此,本研究表明,饥饿应激下大鼠对生长激素不敏感是由于生长激素介导的胞内信号通路改变引起。 相似文献
8.
猪生长激素抗独特型抗体的制备及免疫学鉴定 总被引：1，自引：0，他引：1
应用猪生长激素（Ag）纯品，通过杂交瘤技术制备了猪生长激素单克隆抗体（Ab1）。Ab1经免疫亲和层析柱纯化后免疫新西兰白兔，其血清经饱和硫酸铵纯化后获得猪生长激素抗独特型抗体（Ab2）。再应用ELISA等方法进行鉴别。Ab2与Ab1呈阳性反应，与BALB／c小鼠r球蛋白呈阴性反应；Ab2与Ag竞争结合Ab1；Ab2抑制Ab1与Ag的结合。Ab1是针对猪生长激素纯品的单克隆抗体。Ab2是具有猪生长激素抗原内影像的抗独特型抗体。 相似文献
9.
金鑫燕 《青海畜牧兽医杂志》2015,(3):42-44
本文以牛泌乳性能重要候选基因生长激素及生长激素受体基因为对象,揭示了泌乳性能候选基因的分子育种意义,描述了生长激素在牛生产中的应用历史及生长激素基因影响产奶量的分子机理,介绍了国内外该两种基因多态性对牛泌乳性能影响的研究以及国内外奶牛业分子育种的研究热点,最后对牦牛分子育种进行了展望。 相似文献
10.
动物生长激素及其应用 总被引：9，自引：0，他引：9
畜牧业上使用的动物生长激素主要有牛生长激素（ＢＳＴ）和猪生长激素（ＰＳＴ）。现已证实人工合成的ＢＳＴ具有促进奶牛泌乳的作用；人工合成的ＰＳＴ具有明显的促进生长和提高瘦肉率作用。但是，动物生长激素的安全性和副作用值得重视。本文综述了动物生长激素的作用与作用机理、安全性以及应用前景。 相似文献
11.
Estradiol increases basal growth hormone (GH) concentrations in sheep and cattle. This study sought to determine the effects of estradiol on GH-releasing hormone (GRH)-stimulated GH release in sheep. Growth hormone secretory characteristics, the GH response to GRH, and steady-state GH mRNA concentrations were determined in castrated male lambs treated with 2 different doses of estradiol 17-β for a 28-d experimental period. Although no differences between treatments in mean GH, basal GH, or GH pulse number were observed after 28 d of estradiol treatment, GH pulse amplitude was greater (P < 0.05) in the 2.00-cm implant-treated animals than in the control and 0.75-cm implant group. The effect of estradiol treatment on GRH-stimulated GH release revealed differences between the control and estradiol-treated animals (P < 0.05). The 15-min GH responses to 0.075 μg/kg hGRH in the control, 0.75-cm, and 2.00-cm implant groups, respectively, were 76 ± 10, 22.6 ± 2.1, and 43.6 ± 15.0 ng/mL. Growth hormone mRNA content was determined for pituitary glands from the different treatment groups, and no differences in steady-state GH mRNA levels were observed. There were no differences in the mean plasma concentrations of IGF-I, cortisol, T3, or T4 from weekly samples. Growth hormone release from cultured ovine pituitary cells from control sheep was not affected by estradiol after 72 h or in a subsequent 3-h incubation with estradiol combined with GRH. These data suggest that estradiol has differing actions on basal and GRH-stimulated GH concentrations in plasma, but the increase in pulse amplitude does not represent an increased pituitary sensitivity to GRH. 相似文献
12.
Bhatti SF De Vliegher SP Mol JA Van Ham LM Kooistra HS 《Research in veterinary science》2006,81(1):24-30
This study investigated whether ghrelin, a potent releaser of growth hormone (GH) secretion, is a valuable tool in the diagnosis of canine pituitary dwarfism. The effect of intravenous administration of ghrelin on the release of GH and other adenohypophyseal hormones was investigated in German shepherd dogs with congenital combined pituitary hormone deficiency and in healthy Beagles. Analysis of the maximal increment (i.e. difference between pre- and maximal post-ghrelin plasma hormone concentration) indicated that the GH response was significantly lower in the dwarf dogs compared with the healthy dogs. In none of the pituitary dwarfs, the ghrelin-induced plasma GH concentration exceeded 5 microg/l at any time. However, this was also true for 3 healthy dogs. In all dogs, ghrelin administration did not affect the plasma concentrations of ACTH, cortisol, TSH, LH and PRL . Thus, while a ghrelin-induced plasma GH concentration above 5 microg/l excludes GH deficiency, false-negative results may occur. 相似文献
13.
14.
Five experiments were performed to test the overall hypothesis that exercise might be a useful indicator of growth hormone (GH) and prolactin status in horses. In experiment 1, geldings were exercised for 5 minutes four times at hourly intervals. The prolactin response (P < .05) to the first two exercise bouts was small and increased with successive bouts. There was a consistent GH response (P < .05) for only the first two bouts. In experiment 2, geldings were exercised for 29 to 39 minutes on a treadmill. After the initial bout, half the geldings were supplemented daily with Ca-β-hydroxy-β-methyl butyrate, and all geldings were conditioned for 12 weeks. Exercise bouts at 7 and 12 weeks indicated no effect (P > .1) of supplementation. In experiment 3, treatment of geldings with arginine before exercise increased (P < .001) prolactin concentrations but had no effect (P > .1) on the GH response to exercise. In experiment 4, the repeatability of the GH response to 5 minutes of exercise was determined by exercising eight stallions on six separate occasions. In addition to a large variation in GH response among stallions, there was a large variation within each stallion. In experiment 5, pretreatment with thyrotropin-releasing hormone 2 hours before exercise did not normalize the GH response to exercise. In conclusion, factors affecting the GH response to exercise likely preclude its usefulness as an indicator of GH status in horses. 相似文献
15.
K.A. Heuck L.E. Ellestad J.A. Proudman T.E. Porter 《Domestic animal endocrinology》2009,36(4):186-196
Corticosterone (CORT) can stimulate growth hormone (GH) secretion on embryonic day (e) 12 in the chicken. However, CORT failed to induce GH secretion on e20 in a single report, suggesting that regulation of GH production changes during embryonic development. Secretion in response to CORT during embryonic development is modulated by the thyroid hormones triiodothyronine (T3) and thyroxine (T4). Growth hormone responses on e12 involve both glucocorticoid (GR) and mineralocorticoid receptors (MR); however, involvement of MR has not been evaluated past e12. To further define changes in somatotroph responsiveness to CORT, pituitary cells obtained on e12–e20 were cultured with CORT alone and in combination with T3 and GH-releasing hormone (GHRH). Growth hormone mRNA levels and protein secretion were quantified by quantitative real-time polymerase chain reaction (qRT-PCR) and radioimmunoassay (RIA), respectively. Corticosterone significantly increased GH mRNA and protein secretion on e12; however, mRNA concentration and protein secretion were unaffected on e20. Contributions of GR and MR in CORT responses were evaluated using GR and MR antagonists. Treatment with a GR-specific antagonist effectively blocked the CORT-induced increase in GH secretion on e12. The same treatment on e20 had no effect on GH secretion. These findings demonstrate that GR is directly involved in glucocorticoid stimulation of GH secretion at the time of somatotroph differentiation but is not regulatory at the end of embryonic development. We conclude that positive somatotroph responses to CORT are lost during chicken embryonic development and that GR is the primary regulator of CORT-induced GH secretion. 相似文献
16.
Anita M Oberbauer 《畜牧与生物技术杂志(英文版)》2015,6(1)
Developmental programming of the fetus has consequences for physiologic responses in the offspring as an adult and, more recently, is implicated in the expression of altered phenotypes of future generations. Some phenotypes, such as fertility, bone strength, and adiposity are highly relevant to food animal production and in utero factors that impinge on those traits are vital to understand. A key systemic regulatory hormone is growth hormone (GH), which has a developmental role in virtually all tissues and organs. This review catalogs the impact of GH on tissue programming and how perturbations early in development influence GH function. 相似文献
17.
Bhatti SF Duchateau L Van Ham LM De Vliegher SP Mol JA Rijnberk A Kooistra HS 《Veterinary journal (London, England : 1997)》2006,172(3):515-525
The effects of three growth hormone secretagogues (GHSs), ghrelin, growth hormone-releasing peptide-6 (GHRP-6), and growth hormone-releasing hormone (GHRH), on the release of adenohypophyseal hormones, growth hormone (GH), adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), luteinising hormone (LH), prolactin (PRL) and on cortisol were investigated in young and old healthy Beagle dogs. Ghrelin proved to be the most potent GHS in young dogs, whereas in old dogs GHRH administration was associated with the highest plasma GH concentrations. The mean plasma GH response after administration of ghrelin was significantly lower in the old dogs compared with the young dogs. The mean plasma GH concentration after GHRH and GHRP-6 administration was lower in the old dogs compared with the young dogs, but this difference did not reach statistical significance. In both age groups, the GHSs were specific for GH release as they did not cause significant elevations in the plasma concentrations of ACTH, cortisol, TSH, LH, and PRL. It is concluded that in young dogs, ghrelin is a more powerful stimulator of GH release than either GHRH or GHRP-6. Ageing is associated with a decrease in GH-releasing capacity of ghrelin, whereas this decline is considerably lower for GHRH or GHRP-6. 相似文献
18.
Kisspeptin (Kp) is synthesized in the arcuate nucleus and preoptic area of the hypothalamus and is a regulator of gonadotropin releasing hormone in the hypothalamus. In addition, Kp may regulate additional functions such as increased neuropeptide Y gene expression and reduced proopiomelanocortin (POMC) gene expression in sheep. Other studies have found a role for Kp to release growth hormone (GH), prolactin and luteinizing hormone (LH) from cattle, rat and monkey pituitary cells. Intravenous injection of Kp stimulated release LH, GH, prolactin and follicle stimulating hormone in some experiments in cattle and sheep, but other studies have failed to find an effect of peripheral injection of Kp on GH release. Recent studies indicate that Kp can stimulate GH release after intracerebroventricular injection in sheep at doses that do not release GH after intravenous injection. These studies suggest that Kp may have a role in regulation of both reproduction and metabolism in sheep. Since GH plays a role in luteal development, it is tempting to speculate that the ability of Kp to release GH and LH is related to normal control of reproduction. 相似文献
19.
Previous studies on the effect of growth hormone (GH) on serum insulin concentration in cattle had generated seemingly conflicting results, and little was known about the mechanism by which GH affects serum insulin concentration in cattle, if it does. In this study, we determined whether the effect of GH on serum insulin concentration in cattle could be affected by the nutritional levels of the animal and whether GH increased serum insulin concentration in cattle by directly stimulating insulin release or insulin gene expression in the pancreatic islets. Administration of recombinant bovine GH increased serum insulin concentration in nonlactating, nonpregnant beef cows fed a daily concentrate meal in addition to ad libitum hay, but it had no effect in those cows fed hay only. Both GH treatments for 1 and 24 h increased insulin concentrations in cultures of pancreatic islets isolated from growing cattle. Growth hormone treatment for 24 h increased insulin mRNA expression in cultured bovine pancreatic islets. Growth hormone treatment for 16 h increased reporter gene expression directed by a ∼1,500-bp bovine insulin gene promoter in a rat insulin-producing β cell line. Taken together, these results suggest that exogenous GH can increase serum insulin concentration in cattle, but this effect depends on the nutritional levels of fed cattle, and that GH increases serum insulin concentration in cattle by stimulating both insulin release and insulin gene expression in the pancreatic islets. 相似文献
20.
Yong Zhang Yu-Jing Zhu Zhe Li An-Guo Zhou Jing-Hai Zhang R.G. Bardsley S. Gibson 《Livestock Science》2008,115(2-3):279-286
The aim of the current study was to investigate the effects of a porcine growth hormone releasing hormone (pGHRH) gene plasmid injection in piglets on growth performance and whole body protein turnover. Sixty male Canadian Landrace × Chinese Taihu piglets were assigned to an intramuscular injection of 0 (control), 0.25, 0.5, 1 and 2 mg. All pigs were fed with the same diet (crude protein: 239.8 g/kg, digestible energy: 14.28 MJ/kg) at ad libitum intake. Protein turnover was determined on the 22nd day with a three-pool model by using a single-dosage, end-product analysis method with 15 N-glycine as a tracer. Injection of the pGHRH gene plasmid increased the piglets' growth rate, altered feed intake and decreased feed conversion ratio. It increased plasma growth hormone releasing hormone (GHRH), growth hormone (GH), insulin-like growth factor-I (IGF-I) and somatostatin but reduced serum urea and triglyceride. It reduced the urinary nitrogen excretion and led to higher nitrogen retention as well as the efficiencies of nitrogen retention and digestible N utilization. It increased the rates of protein synthesis, protein breakdown and net protein gain. Excretion of endogenous urinary nitrogen was reduced and nitrogen reutilization rate was improved. Conclusions: Injection of the pGHRH gene plasmid in skeletal muscle stimulated GHRH, GH and IGF-I excretion in piglets. Protein deposition was increased by an increase in protein synthesis and a smaller increase in protein breakdown, which was accompanied by reducing amino acid oxidation and increasing nitrogen reutilization. 相似文献