Estradiol: specific binding by pituitary nuclear fraction in vitro

The nuclear fraction of a homogenate of anterior pituitary has a marked binding affinity for estradiol but not for other hormonal steroids. Characteristics of the uptake of estradiol by pituitary nuclear fraction are like those reported for the uterus. Study in vitro will be useful in elucidating how direct estrogen feedback control of anterior pituitary function is mediated.     

Release of multiple hormones by a direct action of interleukin-1 on pituitary cells

Exposure to bacterial endotoxins has long been known to stimulate the release of anterior pituitary hormones; administration of endotoxin was at one time a common clinical test of anterior pituitary function. Endotoxin is a potent stimulus for production of the endogenous pyrogenic protein, interleukin-1 (IL-1), by macrophages and monocytes. The possibility that IL-1 has a direct effect on the secretion of hormones by rat pituitary cells in a monolayer culture was investigated. Recombinant human IL-1 beta stimulated the secretion of adrenocorticotropic hormone, luteinizing hormone, growth hormone, and thyroid-stimulating hormone. Increased hormone secretion into culture supernatants was found with IL-1 concentrations ranging from 10(-9) M to 10(-12) M. Prolactin secretion by the monolayers was inhibited by similar doses. These concentrations of IL-1 are within the range reported for IL-1 in serum, suggesting that IL-1 generated peripherally by mononuclear immune cells may act directly on anterior pituitary cells to modulate hormone secretion in vivo. Incubation of IL-1 solutions with antibody to IL-1 neutralized these actions. These pituitary effects of IL-1 suggest that this monokine may be an important regulator of the metabolic adaptations to infectious stressors.     

THE ISOLATION IN PURE FORM OF THE INTERSTITIAL CELL-STIMULATING (LUTEINIZING) HORMONE OF THE ANTERIOR LOBE OF THE PITUITARY GLAND

Interstitial cell-stimulating (luteinizing) hormone was isolated from swine pituitary glands. This protein hormone, having a molecular weight of about 90,000 and an isoelectric point of pH 7.45, was shown to be pure by tests in the electrophoresis apparatus of Tiselius and in the ultracentrifuge as well as by its constant solubility. The hormone stimulated the interstitial tissue of the testis or ovary and caused the formation of corpora lutea provided that maturing follicles were present. Under the conditions described, its minimal effective total dose in hypophysectomized immature male rats was about 1 microgram of nitrogen or 6.7 micrograms of hormone. Extracts of swine pituitary with purely follicle-stimulating effects did not cause oestrus in immature hypophysectomized female rats unless luteinizing hormone was also administered.     

miRNA-181b在牛腺垂体中的表达规律及其调控作用研究

[目的]探索m iRNA-181b在成熟（18月龄）和未成熟（1月龄）牛腺垂体中差异表达量及其调控功能。[方法]通过构建成熟（18月龄）和未成熟（1月龄）的延边黄牛腺垂体组织m iRNA cDNA文库,对文库中的m iRNA进行Solexa高通量深度测序,并对公牛腺垂体中的m iRNA进行鉴别。从测序结果中挑选出具有差异表达的m iRNA-181b,经实时荧光定量PCR验证其在不同发育期延边黄牛腺垂体中的表达规律,并通过TargetScanS预测m iRNA-181b的靶基因。[结果]m iRNA-181b在不同发育期牛腺垂体表达量存在显著差异,1月龄公牛腺垂体中m iRNA-181b表达量是18月龄的4.05倍。m iRNA-181b与FSHβ基因3＇非编码区838~844碱基可能是特异结合,其结合碱基为UGAAUGUA。[结论]该试验为FSHβ的转录后调控研究提供了理论依据。     

miRNA-181b在牛腺垂体中的表达规律及其调控作用研究(英文)

[目的]探索miRNA-181b在成熟(18月龄)和未成熟(1月龄)牛腺垂体中差异表达量及其调控功能。[方法]通过构建成熟(18月龄)和未成熟(1月龄)的延边黄牛腺垂体组织miRNAcDNA文库,对文库中的miRNA进行Solexa高通量深度测序,并对公牛腺垂体中的miRNA进行鉴别。从测序结果中挑选出具有差异表达的miRNA-181b,经实时荧光定量PCR验证其在不同发育期延边黄牛腺垂体中的表达规律,并通过TargetScanS预测miRNA-181b的靶基因。[结果]miRNA-181b在不同发育期牛腺垂体表达量存在显著差异,1月龄公牛腺垂体中miRNA-181b表达量是18月龄的4.05倍。miRNA181b与FSHβ基因3 非编码区838 ~844碱基可能是特异结合,其结合碱基为UGAAUGUA。[结论]该研究为FSHβ的转录后调控研究提供了理论依据。     

Identification of a thyroid hormone receptor that is pituitary-specific

Three cellular homologs of the v-erbA oncogene were previously identified in the rat; two of them encode high affinity receptors for the thyroid hormone triiodothyronine (T3). A rat complementary DNA clone encoding a T3 receptor form of the ErbA protein, called r-ErbA beta-2, was isolated. The r-ErbA beta-2 protein differs at its amino terminus from the previously described rat protein encoded by c-erbA beta and referred to as r-ErbA beta-1. Unlike the other members of the c-erbA proto-oncogene family, which have a wide tissue distribution, r-erbA beta-2 appears to be expressed only in the anterior pituitary gland. In addition, thyroid hormone downregulates r-erbA beta-2 messenger RNA but not r-erbA beta-1 messenger RNA in a pituitary tumor-derived cell line. The presence of a pituitary-specific form of the thyroid hormone receptor that may be selectively regulated by thyroid hormone could be important for the differential regulation of gene expression by T3 in the pituitary gland.     

二氢吡啶(Diludin)对产蛋鸡内分泌的影响

１ ０２４羽３００日龄罗曼蛋鸡随机分４组,分别饲喂二氢吡啶（Ｄｉｌｕｄｉｎ）添加量０,１００,１５０,２００ ｍｇ／ｋｇ的４种饲粮,于饲喂后第３０日和第８０日采血和屠宰,研究其对蛋鸡内分泌功能的影响。结果显 示：Ｄｉｌｕｄｉｎ均显著地提高了腺垂体和血清中ＦＳＨ,ＬＨ含量,其中垂体ＦＳＨ和ＬＨ含量随饲喂剂量提高 而增加,血清ＦＳＨ和ＬＨ含量以１５０ ｍｇ／ｋｇ组效果最佳;Ｄｉｌｕｄｉｎ提高了血清Ｔ３含量,Ｔ４差异不显著, ３０日Ｔ３随饲粮中Ｄｉｌｕｄｉｎ递增而增加,８０日１５０,２００ ｍｇ／ｋｇ组与对照组差异显著;饲粮中添加Ｄｉｌｕｄｉｎ 具有改进血清雌二醇（Ｅ２）水平,其中８０ 日 １５０,２００ ｍｇ／ｋｇ组与对照组差异显著;１５０ ｍｇ／ｋｇ Ｄｉｌｕｄｉｎ显 著提高血清中孕酮（Ｐ４）含量;饲粮中添Ｄｉｌｕｄｉｎ显著提高下丘脑和腺垂体中ｃＡＭＰ含量。     

Vasopressin and neurophysin: high concentrations in monkey hypophyseal portal blood

Vasopressin and its binding protein, neurophysin, were measured by radioimmunoassay in the hypophyseal portal blood of monkeys after cannulation of individual long portal veins. Mean vasopressin concentrations (13,800 picograms per milliliter) in portal blood were more than 300 times as high as those in the systemic circulation (42 picograms per milliliter). Neurophysin concentration was approximately 25 times as high in portal as in systemic blood. By immunoperoxidase techniques, high concentrations of neurophysin were demonstrated around portal capillaries of the median eminence. These studies indicate direct secretion of vasopressin and neurophysin into the portal circulation; the quantities secreted during stress may be sufficient to exert significant effects on secretion of anterior pituitary hormone.     

The thymus-adrenal connection: thymosin has corticotropin-releasing activity in primates

Endotoxin-free thymosin fraction 5 elevated corticotropin, beta-endorphin, and cortisol in a dose- and time-dependent fashion when administered intravenously to prepubertal cynomolgus monkeys. Two synthetic component peptides of thymosin fraction 5 had no acute effects on pituitary function, suggesting that some other peptides in thymosin fraction 5 were responsible for its corticotropin-releasing activity. In agreement with these observations, total thymectomy of juvenile macaques was associated with decreases in plasma cortisol, corticotropin, and beta-endorphin. These findings indicate that the prepubertal primate thymus contains corticotropin-releasing activity that may contribute to a physiological immunoregulatory circuit between the developing immunological and pituitary-adrenal systems.     

快速简便地制备猪生长激素

 将猪垂体在酸性（pH5.5）条件下制备垂体匀浆液，经硫酸铵分级分离后，用Sephadex G-100凝胶柱层析纯化，得到电泳纯的分子量为21.7KD的猪生长激素，产率为1.22g/kg新鲜垂体。胫骨法测定具有促生长活性，其氨基酸组成、氮末端氨基酸及电荷不均一等性质均与文献报道基本一致。此法较之前人的方法有简便易行、周期短的优越性，活性组分集中，得率也较高，是制备有活性的猪生长激素较为理想的方法。     

Carcinogenic substances from pituitary glands of cattle

Lipid extracts from the pituitary gland of cattle were prepared which, when injected into a pure strain of white mice, caused development of malignant tumors in 26.8 per cent of the 67 animals injected, which corresponds with the numerical results obtained by investigators working with human liver extracts. Evidently the carcinogenic power of these lipid extracts is low. The tumors developed chiefly in organs at a distance from the site of injection, exhibiting various histological types including carcinoma as well as sarcoma. The tumors developed at an earlier date after injection of extracts from the anterior lobe as compared with those developing after injection of the posterior lobe extracts, the average period of time necessary for their development being 9.3 months for the anterior lobe extracts and 14 months for posterior lobe extracts.     

Beta-adrenergic mechanism of insulin-induced adrenocorticotropin release from the anterior pituitary

Intraperitoneal administration of insulin to control rats and to rats with pituitary stalk transections or with lesions of the median eminence resulted in increased plasma adrenocorticotropin (ACTH) levels. The insulin-induced stimulation of ACTH release was blocked in both the control and lesioned animals by prior treatment with either the beta-adrenergic antagonist propranolol or the glucocorticoid analog dexamethasone. The direct application of insulin to primary cultures of the anterior pituitary did not evoke ACTH release or affect the maximal ability of corticotropin-releasing factor or epinephrine to stimulate ACTH secretion. The results suggest that insulin stimulates ACTH release by a mechanism in which catecholamines of peripheral origin act directly on the anterior pituitary.     

鸡胚垂体生长激素细胞的发生及其变化

为研究鸡胚垂体中生长激素细胞的发生及其在发育过程中的变化 ,分别在鸡胚发育的第 3 5～ 2 0 5天采集鸡胚垂体 ,用免疫组织化学方法研究鸡胚垂体中生长激素细胞的发生和细胞形态、数量、在垂体中的分布特点和在发育过程中的变化。结果表明 ,鸡胚发育中期第 9 5天可观察到少量的生长激素阳性细胞散在分布于垂体后叶 ,细胞多排列成索状或团状 ,细胞之间边界不清 ,细胞核较大。在鸡胚发育的第 12 5天以后 ,生长激素细胞的细胞浆与细胞核比值逐渐变小 ,且均匀分布于腺垂体的后叶。生长激素细胞数在鸡胚发育的第 12 5天之后显著升高 (P <0 0 1) ,在鸡胚发育的第 16 5天 ,生长激素细胞占垂体细胞总数的 9 4 %。以上结果证明鸡胚垂体中生长激素细胞增殖和分化过程主要发生在发育的中期至出壳之前 ,而生长激素细胞的分泌功能在鸡胚发育的后期最为活跃。     

甲低大鼠垂体前叶内IFN-γ样免疫反应阳性物质的表达

应用免疫组织化学(SP)法结合H2O2-DAB黄色呈色法进行显色。IFN-γ样免疫反应阳性物质位于细胞的胞浆内,其阳性细胞只分布于垂体前叶,而后叶和中间部未见免疫反应阳性物质;对照组均未发现免疫反应阳性细胞。甲状腺素低下可以诱导大鼠垂体前叶内IFN-γ样免疫阳性物质的表达,提示甲状腺素低下会影响垂体前叶的内分泌功能。     

GHS-R1a在大鼠下丘脑-垂体-卵巢轴上的定位及其mRNA的周期性表达

取成年SD大鼠的下丘脑、垂体、卵巢组织制成石蜡切片,采用PV-9000两步法免疫组织化学检测GHS-R1a在下丘脑-垂体-卵巢轴上的定位.实时荧光定量PCR检测GHS-Rla mRNA在不同发情周期大鼠F丘脑-垂体-卵巢轴上的表达.结果表明:GHS-R1a主要分布在下丘脑的弓状核、腹内侧核、正中隆起等,腺垂体的嗜色细胞...     

Induced expression of the glucocorticoid receptor in the rat intermediate pituitary lobe

Synthesis and release of pro-opiomelanocortin-derived peptides are under differential regulation in the anterior and intermediate lobes of the pituitary. Glucocorticoids inhibit synthesis of pro-opiomelanocortin-related peptides in the anterior lobe but not in the intermediate lobe. These two lobes are also characterized by differences in neural innervation and blood flow, both of which may represent routes of access for regulatory factors (the intermediate lobe is avascular). Immunoreactive glucocorticoid receptor, which can be demonstrated in many tissues, is absent from the intermediate lobe. Immunocytochemistry was used to demonstrate the presence of immunoreactive glucocorticoid receptor in the intermediate lobe after pituitary stalk transection, neurointermediate lobe grafts to kidney capsule, or monolayer culture of neurointermediate pituitary cells. This appearance of the glucocorticoid receptor is presumably a consequence of removal of intermediate pituitary cells from neural influences that may be responsible for inhibiting their expression under normal conditions in vivo.     

Endothelin stimulation of cytosolic calcium and gonadotropin secretion in anterior pituitary cells

The presence of endothelin, a vasoconstrictor peptide, in the hypothalamus and posterior pituitary suggests that it also regulates neural and other nonvascular target cells. In pituitary gonadotrophs, low doses of endothelin evoked oscillations in the intracellular calcium concentration, and high doses induced a biphasic calcium response. Mobilization of intracellular calcium predominated during the spike phase of the calcium response to endothelin, whereas calcium entry through dihydropyridine-sensitive channels contributed to both the spike and plateau phases of the calcium response. Endothelin was a potent as hypothalamic gonadotropin-releasing hormone (GnRH) in stimulation of gonadotropin release in perifused pituitary cells. Endothelin bound specifically to pituitary cells with a dissociation constant of 70 picomolar, and induced rapid formation of inositol trisphosphate and diacyglycerol. Although intracellular calcium concentration and gonadotropin secretory responses to endothelin were independent to the GnRH receptor, endothelin and GnRH appeared to have a common signal transduction mechanism. These observations suggest that endothelin can act as a neuropeptide to regulate anterior pituitary function.     

苦瓜种子蛋白的双水相提取及抑菌性研究

筛选优化了聚乙二醇(PEG)/硫酸铵双水相的质量分数、分配系数、回收率等影响因素,得到了苦瓜种子蛋白的最佳萃取条件:在26%硫酸铵、22%聚乙二醇条件下,分配系数最小,达0.089,回收率为96%,得到分子量为35.6 kD和12.3kD的苦瓜纯化蛋白。抑菌试验表明,苦瓜种子蛋白对细菌、真菌均有不同程度的抑制作用,且纯化蛋白的抑菌性大于粗提蛋白。     

牦牛生长激素基因分子特性分析

设计特异性引物,利用RT-PCR方法从牦牛脑垂体中扩增出生长激素基因(YGH)编码区全序列,并进行分子特性分析.结果表明:牦牛生长激素基因编码区全长654 bp,包含一个完整的阅读框,编码217个氨基酸.采用生物信息学方法对分子特性进行分析表明:动物生长激素基因在进化上非常保守,牦牛生长激素基因氨基酸序列与黄牛、山羊、绵羊、马、猪、猫和犬的同源性分别为100%、99.1%、98.6%、88.9%8、8.5%、88.9%和89.4%.牦牛生长激素蛋白有2个明显的疏水区域,存在2个强跨膜区和信号肽,是一种分泌型蛋白质,二级结构主要以α-螺旋和不规则卷曲为主,三级结构包含第28-215位氨基酸残基;牦牛生长激素蛋白有较高的抗原指数和抗原表位,这与YGH编码蛋白具有良好的抗原性相一致.