用于鱼类脑垂体内分泌研究的离体灌流培育系统

本实验建立了研究鲤鱼脑垂体碎片促性腺激素（ＧｔＨ）和生长激素（ＧＨ）分泌反应的离体灌流系统。性腺退化鲤鱼的脑垂体碎片可产生稳定和可测的ＧｔＨ和ＧＨ基础分泌;引入２ｍｉｎ脉冲式鲑鱼促性腺激素释放激素类似物（ｓＧｎＲＨＡ）可产生敏感的、恢复迅速和可再现的ＧｔＨ和ＧＨ分泌峰。该系统为鱼类脑垂体激素（ＧｔＨ和ＧＨ）分泌动力学和分泌调节机理的离体研究提供了可靠的手段。     

不同的下丘脑肽和神经递质对鲤鱼促性腺激素和生长激素分泌活动的影响

以１龄性腺发育中期鲤鱼为材料,采用腹腔（ｉ．ｐ）注射的方法,研究不同的下丘脑肽和神经递质对鲤鱼促性腺激素（ＧｔＨ）和生长激素（ＧＨ）分泌的影响。结果表明：促甲状腺激素释放激素（ＴＲＨ）、Ｌ－多巴（Ｌ－ＤＯＰＡ）、甲基睾酮（ＭＴ）、γ－氨基丁酸（ＧＡＢＡ）、促黄体素释放激素类似物（ＬＨＲＨ－Ａ）和三碘甲状腺原氨酸（Ｔ３）都能显著刺激ＧｔＨ的分泌,但最大效应时间各不相同。ＴＲＨ和ＬＨＲＨ－Ａ能促进ＧＨ的分泌,Ｌ－ＤＯＰＡ、ＭＴ、ＧＡＢＡ对血清ＧＨ水平没有明显影响;Ｔ３则对ＧＨ分泌有一定的抑制作用。这说明鲤鱼ＧｔＨ和ＧＨ的分泌除了受各自的下丘脑释放因子和释放抑制因子的双重神经内分泌调控外,还受多种其它相同和不同调节因子的影响,也反映了鲤鱼ＧｔＨ和ＧＨ分泌的神经内分泌调控的复杂性。     

家族性单纯生长激素缺乏症的分子生物学研究

家族性单纯生长激素缺乏症的分子生物学研究于丽莉,王亚新（上海第二医科大学生化教研室,上海２０００２５）关键词生长激素缺乏症,发病机理人的生长、发育和代谢与垂体分泌的一种１９１个氨基酸组成的激素──人生长激素（ｈＧＨ）有关,它的异常会导致人身体生长发育...     

生长激素结合蛋白

动物的生长调控作用中垂体分泌的生长激素 (ＧＨ)起着重要的作用。ＧＨ的生理调控作用的发挥又与血液中的生长激素结合蛋白(ｇｒｏｗｔｈｈｏｒｍｏｎｅｂｉｎｄｉｎｇｐｒｏｔｅｉｎ ,ＧＨＢＰ)以及靶细胞膜上的生长激素受体 (ｇｒｏｗｔｈｈｏｒｍｏｎｅｒｅ ｃｅｐｔｏｒ,ＧＨＲ)的作用不可分割。这三者以及下丘脑的生长激素释放因子 (ＧＨｒｅｌｅａｓｅｆａｃ ｔｏｒ ,ＧＨＲＦ) ,还有垂体的生长抑素 (ｓｏｍａｔｏ ｓｔａｔｉｎ ,ＳＳ)等共同构成动物的内分泌生长轴(ｓｏｍａｔｏｔｒｏｐｉｃａｘｉｓ) ,对动物的生长发育起着决定性的…     

鱼类消化道具有吸收外源生长激素的能力

采用草鱼生长激素夹心式酶联免疫吸附测定法（ＥＬＩＳＡ）,研究了重组鲤生长激素（ｒｃＧＨ）经胃或肠灌注后,胡子鲶、大口鲶和银鲫血清ＧＨ水平的变化规律。胡子鲶、大口鲶直肠分别灌注ｒｃＧＨ（１μｇ／ｇ和５μｇ／ｇ）后,血清ＧＨ水平迅速升高,而在对照组胡子鲶和大口鲶血清中未检测到内源性的ＧＨ,预示处理组血清ＧＨ水平的迅速升高是由ｒｃＧＨ从小肠内转移进血液引起的。胡子鲶胃内灌注ｒｃＧＨ（２５μｇ／ｇ）后,在     

生长激素和生长激素受体的分子生物学

1 .生长激素的结构生长激素 (ｇｒｏｗｔｈｈｏｒｍｏｎｅ ,ＧＨ)一般含有 1 91个氨基酸 ,约 2 2ｋＤ。猪与牛的ＧＨ氨基酸序列具有高度的同源性 (约 90 % ) [1] 。猪和牛的ＧＨ对人没有促进生长的作用 ,可能是猪和牛ＧＨ对人的生长激素受体(ｇｒｏｗｔｈｈｏｒｍｏｎｅｒｅｃｅｐｔｏｒ ,ＧＨＲ )的结合亲和性低于人ＧＨ对人ＧＨＲ的结合亲和性的缘故。ＧＨｍＲＮＡ翻译的初级产物是前生长激素 ,它比成熟ＧＨ在Ｎ端多出 2 6个氨基酸残基的疏水信号肽[2 ] 。通过Ｘ射线衍射技术等研究发现 ,ＧＨ由 4个螺旋组成 ,自Ｎ端至Ｃ端依次为螺旋 1～ …     

虹鳟生长激素cDNA在酵母中的表达

采用聚合酶链式反应（ Ｐ Ｃ Ｒ） 技术对虹鳟生长激素ｃ Ｄ Ｎ Ａ 进行改造。将改造后的基因克隆到含酵母 Ｐ Ｇ Ｋ 启动子的大肠杆菌酵母穿梭质粒ｐ Ｍ Ａ９１ ,转化酿酒酵母 Ｙ３３ ,构建表达鱼生长激素的酵母工程菌 Ｙ３３（ｐ Ｍ Ａｒ Ｇ Ｈ１６） ,并在酵母中获得表达,表达量约占细胞可溶性蛋白总量的３ ％ 。表达产物作为饲料添加剂投喂罗非鱼,具有明显的促进生长作用     

LHRH—A2及无机离子促进草鱼脑垂体离体分泌GH的初步研究

用培养瓶（皿）培养法研究ＬＨＲＨ－Ａ２、Ｃａ＾２＋、Ｋ＾＋对草鱼脑垂体器官分泌ＧＨ的影响。结果表明，１ｎｍｏｌ／Ｌ、１０ｎｍｏｌ／Ｌ、１００ｎｍｏｌ／Ｌ和１０００ｎｍｏｌ／Ｌ的ＬＨＲＨ－Ａ２都能显著促进ＧＨ的分泌；随着Ｃａ＾２＋浓度（０．１、１、３ｍｍｏｌ／Ｌ）的增高ＧＨ的分泌增强，在１ｍｏｌ／Ｌ和３ｍｍｏｌ／Ｌ Ｃａ＾２＋条件下的ＧＨ分泌水平显著高于在０．１ｍｍｏｌ／Ｌ Ｃａ＾２＋条件下的ＧＨ分     

禽胰多肽对体外培养肝细胞分泌功能的影响

禽胰多肽 (ａｖｉａｎｐａｎｃｒｅａｔｉｃｐｏｌｙｐｅｐｔｉｄｅ,ＡＰＰ)是由禽类胰腺合成并分泌的含 36个氨基酸残基的直链多肽。研究表明 ,ＡＰＰ可促进动物采食 ,刺激胃肠道运动及其腺体的分泌。本实验室采用磷酸钙沉淀法从鸡的胰腺中分离出含ＡＰＰ活性组分的ＡＰＰ粗品 ,用该粗品添加于鸡饲料中发现 ,可提高鸡采食量 ,提高鸡腿肌重及单位肌组织中ＤＮＡ及ＲＮＡ的含量 ,促进鸡生长。肝脏是机体的重要代谢器官 ,也是神经内分泌生长轴的重要靶器官。研究表明 ,垂体细胞分泌的生长激素 (ＧＨ)通过与肝细胞膜上的ＧＨ受体结合 ,刺激肝细…     

津白_3侏儒小鼠垂体前叶生长激素细胞的免疫细胞化学研究

津白_３侏儒小鼠（ｄＷ~ｔ）是１９８２年从津白_３纯系小鼠（ＴＡ_３）中发现,进而培育成侏的变种。本实验应用免疫细胞化学技术,对ｄｗ￣ｔ小鼠垂体前叶生长激素（ＧＨ）细胞进行观察,并根据体视学原理进行定量分析,以探讨ｄｗ~ｔ小鼠是否存在垂体发育缺陷。实验结果显示,ｄｗ~ｔ小鼠ＧＨ细胞的体积密度（Ｖｖ）和数密度（Ｎｖ）值均低于正常对照组,Ｐ＜０．０１～０．００１。表明ｄｗ~ｔ小鼠由于垂体前叶ＧＨ细胞数量减少,导致ＧＨ分泌不足,从而形成侏儒。     

Factors influencing herpetofauna abundance and diversity in a tropical agricultural landscape mosaic

Agricultural intensification and the associated factors, including land transformation, are among the major global threats affecting biodiversity especially herpetofauna. However, little information is available about how different factors shape herpetofauna species assemblages in agricultural landscape at different spatial scales from patch (125 – 250m) to the landscape (500 – 1000m). We assessed the diversity of amphibians and reptiles in areas under low and high degrees of agricultural intensification and explored different factors regulating diversity at different spatial scales using four sampling methods. Diversity and abundance of amphibians varied significantly between the two zones, but not for reptiles. Agricultural intensification index (AII), calculated based on agrochemical use and area under agriculture at 250m scale, seemed to affect amphibians both at patch as well as at 500m and 1000m landscape scales. The AII influenced reptilian diversity only at patch and 500m scales. Vicinity of natural forest had a stronger influence on reptilian abundance. Seminatural vegetation impacted herpetofauna diversities at larger spatial scales. The extent of water bodies influenced the reptilian abundance at 250m patch scale and amphibian abundance both at 250m and 1000m scale. Fallow lands affected only reptilian diversity at all spatial scales. Plantation affected amphibian at all scales but reptiles only at the landscape scale. Habitat heterogeneity regulated only amphibian diversity. These results highlight the fact that different patch and landscape-scale factors regulate the diversity of reptiles and amphibians differentially. Such scale-specific information will crucially inform future conservation action for the herpetofauna in the agricultural landscape.     

Anatomy of the Hypophysiotropic Somatostatinergic and Growth Hormone-releasing Hormone System Minireview

The central control of growth hormone (GH) secretion from the pituitary gland is ultimately achieved by the interaction between two hypothalamic neurohormones, somatostatin which inhibits and growth hormone-releasing hormone (GHRH) which stimulates GH release. The regulation of the somatostatin and GHRH release from the hypothalamus is regulated by a range of other neuropeptides, neurotransmitters, neurohormones. In this mini review we attempt to provide a short summary covering the anatomy and chemical characteristics of the various cell populations regulating GH secretion as a tribute to Miklós Palkovits who pioneered the field of functional neuroanatomy of hypothalamic networks.Special Issue Dedicated to Miklós Palkovits.     

生长激素/胰岛素样生长因子1与阿尔茨海默病

生长激素／胰岛素样生长因子-1（GH／IGF-1）轴的合成、分泌、调节及生物学活性与阿尔茨海默病（AD）有密切关系。生长激素（GH）的合成和分泌受生长激素释放激素（GHRH）正向调节。GH／IGF-1轴活性下降导致一系列生理功能变化。GH／IGF-1缺乏可引起衰老及神经退行性变（AD）而导致认知功能的下降,相应激素的补给可以抑制或逆转这种认知障碍。越来越多的证据表明：GH／IGF-1参与AD型痴呆病理过程,对AD有很好的治疗应用前景。本文就生长激素／胰岛素样生长因子1在AD发病中的机理和药理学研究做一综述。     

Growth hormone inhibits growth hormone secretion from the rainbow trout pituitary in vitro

Growth hormone (GH) secretion in salmonids and other fish is under the control of a number of hypothalamic factors, but negative feed-back regulation by circulating hormones can also be of importance for the regulation of GH secretion. Mammalian studies show that GH has a negative feed-back effect on its own secretion. In order to elucidate if GH levels present a direct ultra-short negative feedback loop at the pituitary level GH secretion was studied in intact pituitaries from 50 g fish in an in vitro perifusion system. Following an initial equilibrium period pituitaries were exposed to five increasing concentrations (1-1,000 ng ml(-1)) of ovine GH (oGH) in 20-min steps, before being returned to a GH-free perifusion. Ovine GH caused a significant dose-dependent inhibition of GH secretion and it is concluded that GH can exert a direct negative feedback control on GH secretion at the pituitary level.     

Growth hormone and growth factors during perinatal life

Pituitary growth hormone (GH) is present in early pregnancy in the fetal circulation. The concentrations are higher than ever found during life, due to an unrestrained, basal secretion. GH receptors develop around midpregnancy, when they are present in low concentrations, and there is a rapid increase during the first months of life. The function of fetal GH - characterized by a nearly complete GH resistance - is largely unclear: there is only a small effect on longitudinal growth, and the regulation of growth factors is independent of GH. Possibly, metabolic effects of GH on fat and glucose metabolism and body composition are of greater importance. During the first months of life, the rapid fetal (GH-independent, nutrition-dependent) growth decelerates, a process that is partly compensated by the onset of GH-dependent longitudinal growth.     

Species richness of helminth parasites in Mexican amphibians and reptiles

Abstract. Amphibians and reptiles represent an important group of vertebrates in Mexico; on a global scale 10% of the biodiversity of these groups is found in the country, attaining extraordinarily high levels of endemism (60.7% and 53.7%, respectively). However, fewer than 20% of the known species of amphibians and reptiles in Mexico have been surveyed for helminths, so the inventory is far from complete. We assembled a data base that includes a total of 1246 records (entries) of which 460 correspond to helminths in amphibians and 786 to helminths in reptiles. In total, only 41 species of amphibians (14% of those occurring in Mexico) and only 118 species of reptiles (17% of those occurring in Mexico) have been studied for helminth parasites. From amphibians, 119 species of helminths belonging to 60 genera have been recorded, while 239 species of helminths representing 113 genera have been described from Mexican reptiles. One feature of the distribution of helminths of Mexican amphibians and reptiles is its asymmetry, as seen in representation of helminth groups, host groups and geographical range. However, such statistical asymmetry might be an artefact of sampling effort. Based on our data, we estimate that if all the herpetofauna of Mexico could be studied in the following years, approximately 827 additional species of helminths from amphibians and approximately 1403 from reptiles would be described.     

Neuroendocrine Regulation of Growth Hormone Secretion in Teleost Fishes with Emphasis on the Involvement of Gonadal Sex Steroids

In teleost fishes, growth hormone (GH) appears to play an important regulatory role in several, apparently disparate, physiological events, including reproduction, osmotic or ionic regulation, metabolism, growth and development. GH secretion is regulated by hypothalamic neuroendocrine factors that either act directly on the somatotrophic cells in the pituitary gland, or modulate the secretion or activity of other neuroendocrine factors. In addition, the degree of the neuroendocrine influence on GH release is influenced by the nutritional and reproductive state of the fish; moreover, there appear to be marked species differences in some aspects of this neuroendocrine-physiological condition relationship among fish species. Thus, the neuroendocrine control of GH secretion in fishes is complex, and still poorly understood. The neuropeptides, gonadotrophin-releasing hormone, growth hormone-releasing hormone, thyrotrophin-releasing hormone, neuropeptide Y, serotonin and pituitary adenylate cyclase-activating polypeptide have all been demonstrated to stimulate GH in fish, as has the glutamate agonist, N-methyl-d,l-aspartate. Conversely, somatostatin has a potent inhibitory action on GH release in goldfish and carp, but is less effective in salmon and trout species.This review examines the interactive nature of the neuroendocrine control of GH secretion in fishes, and the manner in which gonadal steroids, directly or indirectly, modulate GH secretion and/or the release, or the activity, of the neuroendocrine factors.     

四川美姑大风顶自然保护区两栖爬行动物资源调查

20 0 2年 8月 1日～ 17日对四川美姑大风顶自然保护区的两栖爬行动物进行了调查。结合前人的工作 ,该保护区共有两栖爬行动物 2 2种 ,其中两栖动物 11种 ,隶属于 9属 7科 2目 ,爬行动物 11种 ,隶属于 9属 4科 2亚目 1目。区系特点为 :(1)物种组成较丰富 ;(2 )都属于东洋界物种 ,没有古北界的成分 ;(3)区系组成较简单 ,以喜马控雅 -横断山区型和南中国型为主 ;(4 )特有种所占比例高。 (5 )既古老又具年轻的特点。美姑县新纪录 6种 ,大凉疣螈为国家Ⅱ级重点保护野生动物 ,横斑锦蛇为四川省重点保护野生动物。美姑大风顶自然保护区两栖爬行动物物种多样性和生境多样性较高 ,对于生物多样性保护和研究横断山脉两栖爬行动物物种组成及区系特征具有一定意义。     

Growth hormone-releasing factor: a new chapter in neuroendocrinology

The isolation and characterization of growth hormone-releasing factor (GRF) has initiated a new and exciting era in our understanding of the neuroendocrine regulation of pituitary growth hormone (GH) secretion. This report briefly describes the isolation and characterization of GRF, factors which modulate the GH response to GRF and the effects of chronic administration and deprivation of GRF on somatic growth. The intent of this report is to serve as a general introduction on biochemical and physiological aspects of GRF. The following reports from this symposium will then cover many of these topics in much greater detail.     

Growth hormone-releasing hormone neurons in the anestrus cat do not express progesterone receptors

Ovarian steroids have been implicated in the regulation of growth hormone (GH) secretion in several species and increased progesterone secretion has been associated with elevated circulating GH levels in the cat. These high GH concentrations may be due, at least in part, to a direct action of progesterone on growth hormone-releasing hormone (GHRH) neurons. Using standard immunocytochemical methods coupled to high-temperature antigen retrieval, the objective of this study was to determine whether progesterone receptors were colocalized in GHRH neurons of the anestrus cat. GHRH perikarya were restricted to the infundibular nucleus and the ventral ventromedial nucleus and although frequently surrounded by numerous progesterone receptor-immunoreactive cells, none was colocalized. This study, therefore, provides evidence that, in the adult anestrus female cat, GHRH neurons do not express nuclear progesterone receptors.