左旋十八甲基炔诺酮对大鼠卵巢颗粒细胞和垂体细胞激素合成及分泌的影响

研究了左旋十八甲基炔诺酮对大鼠卵巢颗粒细胞和垂体细胞激素合成及分泌的直接作用。结果显示左旋十八甲基炔诺酮单独作用于无血清培养的颗粒细胞时,抑制雌二醇的合成,但刺激孕酮的分泌;在与促卵泡素合并处理时,颗粒细胞雌二醇、孕酮的分泌量随着左旋十八甲基炔诺酮浓度的增加而增加。利用促性腺激素生物测定方法证明大鼠整体用左旋十八甲基炔诺酮处理后,垂体中促卵泡素和促黄体生成素活性明显下降;同时外周血清中促卵泡素的活性亦下降。培养的垂体单纯用左旋十八甲基炔诺酮处理后,其培养液经生物测定呈现抑制颗粒细胞雌二醇和孕酮的分泌,促性腺激素释放激素可减弱左旋十八甲基炔诺酮的抑制作用。提示左旋十八甲基炔诺酮除通过垂体卵巢轴系起作用外,还能直接作用于卵巢。     

左旋十米甲基炔诺酮对大鼠卵巢颗粒细胞和垂体细胞激素合成及分泌的 …

研究了左旋十八甲基炔诺酮对大鼠卵巢颗粒细胞和垂体细胞激素合成及分泌的直接作用。结果显示左旋十米甲基炔诺酮单独作用于无血清培养的颗粒细胞时,抑制雌二醇的合成,但刺激孕酮的分泌;在与促卵泡素合并处理时,颗粒细胞雌二醇、孕酮的分泌量随着左旋十米甲基炔诺酮浓度的增加而增加。利用促性腺激素生物测定方法证明大鼠整体用左旋十八甲基炔诺酮处理后,垂体中促卵泡素和促黄体生成素活性明显下降;同时外周血清中促卵泡素的活     

人卵泡液中有卵泡促性腺激素释放肽

过去曾经多次报道,卵泡液和精液能促进脑垂体促性腺激素分泌,但对其中活性物质的化学结构尚未了解。美国李卓浩等报道,从人卵泡液中分离到一个14肽,即人卵泡促性腺激素释放肽(hF-GRP)。在离体条件下,hF-GRP 具有促进垂体促性腺激素分泌的活性。用小鼠垂体培养法测定,其促进卵泡刺激素(FSH)或黄体生成素(LH)释放的 ED_(50)值分别为每管2.0μg/ml(1.2nmol/L)和2.6μg/ml(1.6nmol/L),活性比下丘脑黄体生成素释放激素(LHRH)低。初步资料表明,hF-GRP 在大鼠完整垂体培养系统及垂体     

发现绵羊垂体分泌的新激素——促肾素

现在已清楚许多激素,包括生长激素、促肾上腺皮质激素、胰岛素、雄激素、甲状腺素、糖皮质激素和盐皮质激素,在增加器官重量、RNA和蛋白质合成、DNA合成和有丝分裂活性以及鸟氨酸脱羧酶活性方面能促进肾生长。除了这些促进肾生长的激素以外,Nicholson等证明,还有一种绵羊垂体分泌的多肽片断能促肾增大,其依据是这一因子能增加经阉割并切除垂体的大鼠肾重量。经生化分析这一多肽片断主要由LH组成,不含生长激素、促肾上腺皮质激素、γ-促脂解激素、加压素和催乳素,而仅含少量的TSH和FSH。每天给切除垂体的大鼠注射生长激素、促肾上腺皮质激素、催乳素、TSH和FSH都不能刺激肾生长。为了解答垂体分泌的促肾素(renotropin)活性是否归因于LH内在活性的疑问,Nicholson等检测了     

促甲状腺素释放激素对提高母貂乳量与仔貂成活率的研究

丘脑下部促甲状腺素释放激素(TRH)调节控制垂体促甲状腺素(TSH)和催乳素(Pro-laetin,PRL)的分泌。TRH通过激发垂体TSH和PRL的分泌,提高家畜产奶量和促进新生幼     

性腺素:卵泡液中刺激垂体促性腺激素分泌的肽

作者给22天的未成年雌性大鼠注射孕马血清促性腺激素,于25天处死,取卵巢,将卵泡液处理后得到大鼠卵泡液性腺素(gonadocrinin)的粗制剂。将此性腺素制剂加入垂体细胞单层培养以后,培养液中的LH和FSH均增加。而以同样方式处理大鼠肝脏所得到的制剂无此作用。在大鼠间情期第二天,静脉注射该性腺素,血清LH水平的变化与用LRF处理的大鼠相似。这说明,在体及离体条件下,性腺素均能刺激垂体分泌促性腺激素。离体条件下,性腺素仅仅刺激LH和FSH的分泌,对其它几种垂体激素(PRL、GH及TSH)的分泌均无影响。这提示性腺素的作用具有特异性。用放射免疫测定法证明,该性腺素制剂中没有可测出量的FSH、LH、雌激素、孕酮及睾丸酮。     

促性腺激素释放激素类似物对长臀wei脑垂体促性腺激素分泌的影响

采用离体灌流孵育技术和促性腺激素的放射免疫测定方法,对长臀wei(Cranoglanis bouderius)脑垂体碎片促性腺激素的分泌进行了研究。结果表明：持续的促性腺激素释放激素类似物(GnRH-A)能显著刺激退化期的长臀wei离体脑垂体碎片促性腺激素(GTH)的分泌,并且长臀wei脑垂体碎片对持续的GnRH-A刺激未表现出脱敏性,该结果与胡子鲇和鲇鱼相似,而与金鱼和鲤科鱼类不同;重复脉冲GnRH-A刺激对长臀wei脑垂体碎片GTH分泌具有促进作用,而且存在剂量依存关系,与鲇鱼和鲤科鱼类相类似。上述结果表明在长臀wei的人工繁殖中可以用持续高浓度GnRH-A刺激对长臀wei进行催熟和催产。     

重组人促性腺激素释放激素及导肽的分离纯化与活性分析

对含重组人促性腺激素释放激素(GnRH)及导肽(LEP)的工程菌株进行诱导表达,分离纯化GnRH/LEP并进行生物学活性分析.工程菌IPTG诱导,收获的菌体经超声破碎后,裂解液用Glutathione-Sepharose 4B亲和层析纯化GST-GnRH/LEP融合蛋白,经CNBr裂解、Sephadex G-25柱脱盐、QAE-Sepharose FF阴离子交换柱层析和RP-C18柱脱盐,得到纯度大于98%的重组GnRH/LEP.Western blot表明表达产物均具有GrRH抗原特异性.生物学活性分析表明:该表达产物可促进小鼠次级卵泡向成熟卵泡发育,可提高其血清中E2含量.     

大鳞大马哈鱼垂体生长激素的分离、纯化与鉴定

应用ConA-Sepharose 4B亲和层析、凝胶过滤及离子交换层析等技术从大鳞大马哈鱼(Oncorhynchus tshawytscha)垂体中分离纯化了具有生物活性的生长激素(sGH)。用放射受体测定法(RRA)检测sGH组分的生物活性,结果表明纯化的8GH制品具有与兔肝细胞GH受体结合的生物活性。用放射免疫测定法(RIA)和酶联免疫吸附测定法(ELISA)分别检测了另两种垂体激素-催乳激素(PRL)和促性腺激素(GTH)在纯化的sGH制品中的残留量均在0.5％以下。用SDS-聚丙烯酰胺凝胶电泳SDS-PAGE评价sGH制品的电泳纯度并测定了其分子量为22000左右。等电聚焦电泳表明该种鱼GH由等电点分别为6.3和6.6的两种形式的分子组成。     

一种促分裂活性降低的hbFGF突变体的表达及纯化(英文)

为了降低由人碱性成纤维细胞生长因子(hbFGF)的广谱促分裂活性引起的潜在副作用,用中性氨基酸丙氨酸取代了hbFGF第108位的丝氨酸,构建了促分裂活性降低的hbFGF突变体(mhbFGF)。IPTG诱导突变体在大肠杆菌BL21(DE3)中高效表达。mhbFGF的表达量约为全菌体蛋白的30％。通过离子交换和肝素亲和层析从菌体上清中纯化目标蛋白。MTT法检测促分裂活性表明,mhbFGF的促分裂活性显著低于野生型hbFGF。纯化的:mhbFGF可用于进一步的药效和安全性研究。     

Thyrotropic activity of salmon pituitary glycoprotein hormones in the Hawaiian parrotfish thyroid in vitro

The thyrotropic activities of salmon pituitary extract, thyroid-stimulating hormone (TSH), gonadotropins (GTH), and glycoprotein fractions obtained during purification of salmon TSH and GTH were measured using the parrotfish thyroid culture system. Purified salmon TSH was approximately 1,000 times more potent than bovine TSH in stimulating thyroxine release into the culture medium. Most of the forms of salmon GTH had no thyrotropic activity. One of the forms of salmon GTH (GTH-F) and three chromatofocusing fractions (CF-B, -C, and -E) that were devoid of activity in the coho salmon in vivo had some thyrotropic activity in the parrotfish thyroid culture. Whether the activity of these fractions was due to contamination with TSH, less potent forms of TSH, or inherent thyrotropic activity of a form of GTH is discussed. These results indicate that the parrotfish thyroid culture system can be used to detect thyrotropic activity of fractions obtained during the purification of teleost TSH.     

Immunohistochemical Identification of the Adenohypophysial Cells in the Indian Paddy Field Frog,Rana limnocharis

Cells of the pituitary pars distalis (PD) and pars intermedia (PI) in the frog Rana limnocharis have been identified by an unlabelled antibody enzyme method using antisera developed in rabbit against mammalian hypophysial hormones. On the basis of their immunoreactivity, six types of cells, viz. thyrotropic (TSH), gonadotropic (GTH), prolactin (PRL), growth hormone (GH), corticotropic (ACTH) and melanotropic (MSH), cells have been recognized. GTH and PRL cells are distributed throughout the PD. GH cells usually occur in the anterodorsal and central region of the gland. Immunoreactive TSH cells are fewer in number and are localized in the ventromedian region of the PD. Cells showing immunoreactivity to ACTH 1–24 antiserum are encountered in the rostroventral part of the PD. Cells of the PI also show immunoreactivity to ACTH 1–24 antiserum. PI cells cross-react with α-MSH antiserum at all dilutions up to 1: 50 000. However, when the same antiserum was used at dilutions up to 1: 20 000, the ACTH cells of the PD also showed cross-reactivity.     

Effects of estradiol and mammalian LHRH on the ultrastructure of the pars distalis of the eel

Summary Male silver eels were injected with estradiol-17 (E2) to induce the development of gonadotropic (GTH) cells. They were subsequently injected with luteinizing hormone-releasing hormone (LHRH). Exocytotic figures and the lysis of some large globules and granules were observed. Morphometric studies showed a significant increase in the percentage of vacuoles after 4 and 6 injections of LHRH and a slight but significant decrease of granules. This response did not, however, occur in all GTH cells which never appeared completely degranulated and did not reach a vesicular stage.Hemi-pituitaries of E2-pretreated eels were incubated with or without LHRH (20 min to 2 h). Although typical exocytoses were not detected, an increased number of small granules near the basal lamina and lytic processes (globules with a raspberry-shaped structure, granules with variable electron density) were observed in the LHRH-incubated hemi-pituitaries compared with those kept in a control medium. The structure of GTH cells and their response to LHRH has been studied only under conditions of artificial stimulation, and their functional similarity to GTH cells of spontaneously maturing eels is discussed.Large female eels had unstimulated GTH cells. Growth hormone (STH), thyrotropic (TSH) and prolactin (PRL) cells were stimulated after E2 and LHRH. As with GTH cells, they regressed slowly after treatment was discontinued.     

Isolation and characterization of two coho salmon gonadotropins, GTH I and GTH II

Two gonadotropins, GTH I and GTH II, were isolated from pituitaries of spawning coho salmon (Oncorhynchus kisutch) using sequential extractions with ammonium acetate (pH 9.0) and 40% ethanol, precipitation with 80% ethanol, gel filtration chromatography (Sephadex G-100), anion-exchange chromatography (Mono-Q Sepharose), and gel filtration chromatography (Sephadex G-75). Coho salmon GTH I and GTH II stimulated steroidogenesis in vitro in a similar dose-dependent manner when incubated with either ovaries or testes of prepubertal coho salmon. An in vivo bioassay using coho salmon parr demonstrated that coho salmon GTH I and GTH II did not contain thyrotropic activity. Molecular weights were estimated by gel filtration chromatography to be 43,000 and 39,000 for GTH I and GTH II, respectively. Analysis of coho salmon GTH I and GTH II on reversed-phase high-performance liquid chromatography (rpHPLC) revealed that they consist of alpha and beta subunits with N-terminal amino acid residues of Tyr, Gly (alpha, beta of GTH I) and Tyr,Ser (alpha, beta of GTH II). Coho salmon GTH I-beta and GTH II-beta differed from each other in amino acid composition, N-terminal amino acids (Gly vs. Ser), and molecular weights in SDS-PAGE (19,000 vs. 20,000) and had a high degree of chemical similarity to chum salmon GTH I-beta and GTH II-beta, respectively. Specific rabbit antisera to the beta subunits of coho salmon GTH I and GTH II were generated. The observation of two GTHs with distinctly different chemical characteristics in coho salmon is similar to what has previously been found in chum salmon.     

The Thyrotropic Cell in the Atlantic Salmon,Salmo salar

The thyrotropin (TSH) producing cells are distributed in the rostral and proximal pars distalis. This cell type is the smallest and most infrequent cell of the adenohypophysis. Its cytology is similar to the smallest gonadotropic (GTH) cells although the two cell types can be separated by the size of the small secretory granules (diameter less than 200 nm) in the TSH cells. In presmolts and smolts the cells are more numerous than in parr and adult salmon and have cytological features indicating an increased activity. This was also the case after intraperitoneal injections of synthetic TRH. Antisera to carp GTH and salmon GTH cross-reacted with both the GTH and the TSH cells. Anti-human TSH cross-reacted only with the TSH cells which confirms the assumption of antigenic similarity between human and fish TSH.     

人红细胞生成素的分离、纯化及鉴定

 用自制的苯基-琼脂糖CL-4B和羟基邻灰石等层析材料,从再生障碍性贫血病人尿中分离、纯化制得了红细胞生成素(EPO)。用多血小鼠红细胞~(56)Fe参入法测定该制品在体内的生物活力。用小鼠与人骨髓红系祖细胞培养法测其在体外的生物活力。实验结果说明,我们自制的EPO制品,不仅能用于动物,也能用于人骨贿红系祖细胞的培养。用Azocoll法测该制品中蛋白水解酶活力为阴性。     

Purification and characterization of monoclonal antibodies against the free α-subunit of human chorionic gonadotrophin

Monoclonal antibodies (Mabs) against human chorionic gonadotropin hormone (hCG) were raised by hybridoma technology using Sp2/0 myeloma cells as fusion partner. Sixty-five percent of the total culture wells exhibited hybrid growth and 8% of the total wells (13 culture wells) contained anti-hCG secreting hybrids. A positive hybrid cell line secreting antibodies against the free alpha-subunit of hCG was cloned twice by limiting dilution method and eighty four clones were obtained that secreted monoclonal antibodies anti-alpha hCG. One of these hybridoma clones (1C4) secreting monoclonal antibodies against the free alpha-subunit of hCG was selected for purification and characterization purposes. This hybridoma cell line secreted monoclonal antibodies of IgG1 subclass, which were purified by affinity chromatography on Protein A Sepharose CL-4B column with a final relative recovery of antibody activity of 75% and a purification factor of about 12. The purified preparation was analyzed by SDS-PAGE, native PAGE, and IEF. Specificity studies of this Mab revealed that it recognized specifically an epitope on the free alpha-subunits of hCG, FSH, LH, and TSH as determined by enzyme immunoassays. On the other hand, this Mab exhibited crossreactivity with other pituitary hormones either as free subunits or intact molecules as follows: alpha hCG 100%; intact hCG 1.8%; beta hCG 0.14%; alpha FSH 24.5%; intact FSH 0.8%; beta FSH 0.09%; alpha LH 20.5%; intact LH 0.9%; beta LH 0.08%; alpha TSH 50.5%; intact TSH 3.7%; beta TSH 0.07%; The affinity constant (K) of this Mab with respect to free alpha-subunit of hCG was found to be 1.5 x 10(7) I/mol as determined by the simple antibody dilution analysis method.     

Accumulation of glycoprotein gonadotropin in the pituitary of juvenile rainbow trout in response to androgens and C21-steroids,including 11-steroids

Summary Effects of steroids on the accumulation of glycoprotein gonadotropin (GTH) in pituitaries of juvenile trout were investigated by means of scanning cytophotometry applied to immunocytochemical preparations, and with the use of a radioimmunoassay. Effects on other aspects of GTH-cell activity were analyzed by measuring the size of the gonadotrops and their nuclei.Progesterone added to aquarium water and methyltestosterone incorporated into the food showed a pronounced stimulatory effect on the accumulation of GTH. To a lesser extent, treatment with cortisol, cortisone, and desoxycorticosterone acetate administered to aquarium water, and 11-hydroxy-androstenedione added to the food resulted in an increase of the hypophysial content of GTH. Steroids stimulating the accumulation of GTH in the pituitary also exhibited a positive effect on GTH-cell activity as indicated by an increase in the size of gonadotropic cells. Progesterone incorporated into the food did not influence the GTH-content and the GTH-cell activity. It is suggested that the route of administration of an exogenous steroid is essential for its effect on GTH cells in trout.Comparison of GTH values reveals an excellent correlation between the data from the radioimmunoassay and those from the corresponding densitometric measurements. No correlation was observed between values of morphometrically determined GTH-cell activity and the densitometric values reflecting hypophysial GTH content.     

Effects of Castration and Androgen-treatment on Pituitary and Testes of the Three-spined Stickleback,Gasterosteus aculeatus L., in the Breeding Season

Methyltestosterone (MT) (35 μg/l aquarium water) suppresses steroid production in the testes of sham-operated fish, as studied enzyme histochemically. This treatment also diminishes the volume of the proximal pars distalis, as well as the area of the gonadotropic (GTH) cell nuclei. Such effects were not found in MT-treated castrated fish. Castration alone led to a partial degranulation of the GTH-cells as compared with sham-operated controls. Extensively dilated granulated endoplasmic reticulum was found in the GTH-cells of some of the castrated animals and also in GTH-cells of some castrated fish that had been treated with MT. The possibility of a non-steroidal feedback mechanism from testes to pituitary is discussed. No effects of the treatments were observed on prolactin cells and on the second basophilic cell type (GTH II?, TSH?).