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生长激素(growth hormone,GH)对动物的生长发育具有重要的生理作用.GH与生长激素受体(growth hormone receptor,GHR)结合后才会发挥一系列的生理作用.近年来,人们对GHR结构和功能的研究取得了巨大的进展,并取得了一些重大的突破.现在已清楚了GH-GHR轴激活一些相关的信号转导通路,但并非所有的通路都依赖酪氨酸激酶.作者从以下几个方面总结了GHR作用下的信号转导机制的研究进展:GHR的结构与功能;依赖JAK2的相关信号通路;不依赖JAK2的相关信号通路;GHR信号负调控因子.阐明这些复杂机制,对进一步了解GH对动物不同的生理和病理作用具有重要意义.  相似文献   

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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.  相似文献   

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The purpose of this study was to understand the change trend of growth hormone (GH) and growth hormone receptor (GHR) in serum of Mashen and Large White pigs during the period from 0 to 6 months of age,and to analyze the influence of GH and GHR on growth rate.The method of ELISA was used to detect the concentration of GH and GHR in serum of Mashen and Large White pigs from 0 to 6 months of age.The results showed that the variation trends of GH in Mashen pig was roughly the same as in Large White pig,the GH concentration was increased with age increasing after birth and reached the peaks at 4 and 5 months of age for Mashen and Large White pigs,respectively,and then decreased gradually.The serum GH concentration in Mashen pig was a little greater than that in Large White pig at 3 and 4 months of age,on the contrary,the serum GH concentration in Large White pig was greater than that in Mashen pig at other months.During the period from 0 to 6 months of age,the difference of GHR concentration in serum was not significant in Mashen pig (P>0.05).In Large White pig,the serum GHR concentration at 1 month of age was lowest,and was significantly lower than that at 4 and 6 months of age (P<0.01;P<0.05).During the period of 0 to 2 months of age,the GHR concentration in Mashen pig was greater than that in Large White pig,but the difference was extremely significant only at 1 month of age (P<0.01).Conversely,the serum GHR concentration in Large White pig was greater than those in Mashen pig during the period from 3 to 6 month of age,there was significant difference at 4 and 6 months of age (P<0.05),and there was extremely significant at 5 months of age(P<0.01).The concentration of GH and GHR in serum was related to the developmental stages and genetic background of pig,and its change trend was in accordance with the trend of growth rate.  相似文献   

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试验旨在探讨马身猪和大白猪血清中生长激素(growth hormone,GH)及其受体(growth hormone receptor,GHR)在生长发育过程中的变化规律,采用ELISA方法检测马身猪和大白猪0~6月龄血清中GH和GHR的浓度。结果表明,马身猪和大白猪在0~6月龄血清中GH浓度变化趋势基本相似,随着日龄的增长,血清中GH浓度呈逐渐上升的趋势,分别在4和5月龄时达到最高值,随后又逐渐降低,但与峰值无显著差异(P>0.05),在3和4月龄时,马身猪血清中GH浓度略高于大白猪,而在其他月龄,大白猪血清中GH均高于马身猪;0~6月龄,马身猪血清中GHR浓度无显著差异(P>0.05),大白猪血清中GHR的含量在1月龄时最低,与4月龄差异极显著(P<0.01),与6月龄差异显著(P<0.05),其他月龄间差异不显著(P>0.05),0~2月龄,马身猪血清中GHR含量高于大白猪,但只有在1月龄时差异达极显著水平(P<0.01);3~6月龄,大白猪血清中GHR含量高于马身猪,且在4和6月龄时差异显著(P<0.05),5月龄时差异极显著(P<0.01)。血清中GH和GHR浓度与猪的发育阶段和遗传背景有关,其变化规律与猪生长速度的变化趋势相一致。  相似文献   

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Regulation of protein and energy metabolism by the somatotropic axis.   总被引:8,自引:0,他引:8  
The somatotropic axis plays a key role in the co-ordination of protein and energy metabolism during postnatal growth. This review discusses the complexity of the regulation of protein and energy metabolism by the somatotropic axis using three main examples: reduced nutrition, growth hormone (GH) treatment and insulin-like growth factor-1 (IGF-1) treatment. Decreased nutrition leads to elevated GH secretion, but it reduces hepatic GH receptor (GHR) number and plasma levels of IGF-1; it also changes the relative concentrations of IGF binding proteins (IGFBPs) in plasma. GH treatment improves the partitioning of nutrients by increasing protein synthesis and decreasing protein degradation and by modifying carbohydrate and lipid metabolism. However, these well-established metabolic responses to GH can change markedly in conditions of reduced nutritional supply or metabolic stress. Short-term infusion of IGF-1 in lambs reduces protein breakdown and increases protein synthesis. However, long-term IGF-1 administration in yearling sheep does not alter body weight gain or carcass composition. The lack of effect of IGF-1 treatment can be explained by activation of feedback mechanisms within the somatotropic axis, which lead to a reduction in GH secretion and hepatic GHR levels. The somatotropic axis has multiple levels of hormone action, with complex feedback and control mechanisms, from gene expression to regulation of mature peptide action. Given that GH has a much wider range of biologic functions than previously recognized, advances in research of the somatotropic axis will improve our understanding of the normal growth process and metabolic disorders.  相似文献   

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Perturbations in endocrine functions can impact normal growth. Endocrine traits were studied in three dwarf calves exhibiting retarded but proportionate growth and four phenotypically normal half-siblings, sired by the same bull, and four unrelated control calves. Plasma 3,5,3'-triiodothyronine and thyroxine concentrations in dwarfs and half-siblings were in the physiological range and responded normally to injected thyroid-releasing hormone. Plasma glucagon concentrations were different (dwarfs, controls>half-siblings; P<0.05). Plasma growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin concentrations in the three groups during an 8-h period were similar, but integrated GH concentrations (areas under concentration curves) were different (dwarfs>controls, P<0.02; half-siblings>controls, P=0.08). Responses of GH to xylazine and to a GH-releasing-factor analogue were similar in dwarfs and half-siblings. Relative gene expression of IGF-1, IGF-2, GH receptor (GHR), insulin receptor, IGF-1 type-1 and -2 receptors (IGF-1R, IGF-2R), and IGF binding proteins were measured in liver and anconeus muscle. GHR mRNA levels were different in liver (dwarfs相似文献   

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生长激素受体基因表达的研究进展   总被引:4,自引:1,他引:3  
生长激素(growth hormone,GH)在促进动物生长、发育等代谢过程中起着重要作用。长期以来人们在研究动物生长发育机制及其调控时,主要着眼于提高生长激素水平。然而GH必须与靶器官上生长激素受体(growth hormone receptor,GHR)结合,由GHR介导将信号传入细胞内才能发挥作用。大量研究结果显示,动物生长速度与GH水平并不完全平行,但与肝脏GHR呈明显正相关。生长快的肉鸡血液中GH和垂体GH mRNA水平比生长慢的蛋鸡低,而肝脏GHR水平比蛋鸡高;患侏儒症动物血液中GH浓度却比正常动物高,而GHR胞外部分缺失或功能不全。可见GHR基因表达对动物生长发育调控起着至关重要的作用。  相似文献   

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