促卵泡激素结合片段通过P13K／Akt—cyclinD1通路抑制卵巢癌细胞增殖活性

目的：研究促卵泡激素（FSH）结合片段对卵巢上皮性细胞癌细胞株hey增殖活性的影响。方法：应用卵巢上皮性细胞癌细胞株hey作为实验对象,分别加入FSH、FSH结合片段、FSH＋FSH结合片段。用四甲基偶氮唑蓝（MTT）法检测卵巢癌hey细胞的生长状况,Westernblot检测cyclinD1、Akt、pAkt分子的表达。结果：FSH对卵巢癌hey细胞的生长有明显的促进作用,细胞生长活性提高21％。FSH结合片段对卵巢癌细胞的生长有明显抑制作用,对细胞平均抑制率为22％,且能下调cyclinD1的表达,在2．5×10^-9Mol／L达70％。FSH结合片段对FSH有竞争抑制作用,细胞抑制率为18％,能抑制FSH上调cyclinD1的作用,抑制率为61％。FSH能上调pAkt的表达,对Akt的袁达没有明显影响,在40mlU／ml的浓度时pAkt／Akt上调率达224％。FSH结合片段对Akt的表达没有明显影响,但能明显下调pAkt的表达,且呈时间依赖性（在15分钟时达66％）和剂量依赖性（在2．5×10^-9Mol／L达31％）。FSH结合片段能抑制FSH上调pAkt的作用,抑制率为80％。结论：FSH结合片段可通过抑制FSH诱导的P13FdAkt-cycl—inD1信号通路进而抑制上皮性卵巢癌hey细胞的增殖活性,     

Cosmc基因在卵巢癌中生物学功能的研究

目的:明确Cosmc基因在卵巢癌细胞中的生物学功能。方法:本研究采用慢病毒转染技术,在卵巢癌细胞A2780和SKOV3中过表达Cosmc基因,MTT实验、细胞凋亡实验以及Transwell侵袭实验对过表达Cosmc后卵巢癌细胞在生长、凋亡、侵袭等方面的影响。结果:慢病毒转染卵巢癌细胞A2780和SKOV-3后,Cosmc的蛋白表达显著提高;MTT结果显示,与空载体对照组相比,过表达Cosmc的卵巢癌细胞生长能力显著减弱;流式细胞术结果表明Cosmc过表达的卵巢癌细胞凋亡数较空载体对照组细胞显著增加;Transwell实验显示Cosmc过表达的细胞侵袭和迁移能力较空载体对照组显著减少。结论:卵巢癌细胞系中过表达Cosmc基因能抑制卵巢癌细胞的生长和侵袭并促进细胞凋亡。     

HMBA诱导人肝癌SMMC-7721细胞分化的观察

本文研究HMBA对人肝癌SMMC-7721细胞的诱导分化作用.细胞生长曲线测定和细胞分裂指数观察显示HMBA可明显抑制细胞增殖,细胞生长抑制率达64.14%,分裂指数抑制率为53.88%.光镜和透射电镜观察可见HMBA能诱导人肝癌SMMG-7721细胞形态和超微结构发生恢复性改变.生化检测或免疫细胞化学方法观察显示,HM-BA处理后细胞γ.谷氨酸转肽酶(γ-GT)活性和甲胎蛋白(AFP)、增殖细胞核抗原(PCNA)表达均降低,而酪氨酸.酮戊二酸转氨酶(TAT)活性增强.流式细胞仪分析表明HMBA引起细胞发生G0/G1期阻滞.以上结果表明HMBA能有效抑制人肝癌细胞恶性增殖活性,逆转肝癌细胞恶性形态与超微结构特征,改变肝癌细胞相关酶活性和抗原表达,引发G0/G1期阻滞,从而对肝癌细胞具有明显的诱导分化作用.     

长效人促卵泡激素CHO细胞株的构建及其体内活性

促卵泡激素(FSH)是具有促进卵泡与睾丸发育作用的一种垂体糖蛋白激素。因其体内半衰期较短,临床上需要连续10 d以上每天注射,病人使用非常不方便。本文旨在通过提高糖基化程度,研制一种长效FSH。通过一段含有两个N-糖基化位点的连接序列,将人FSHα链与β链cDNA融合,并插入pcDNA3.1(+)表达载体。表达载体转染CHO-K1细胞后,通过G418筛选得到阳性单克隆细胞,并经PCR和Western blotting证实。该重组FSH为单链蛋白,分子量约为49 kDa。经无血清培养,工程细胞株培养上清液中重组FSH的表达量可达3 mg/L。单次注射该重组FSH能够促进大鼠卵巢发育与卵泡成熟,且药效与连续8次注射Folltropin-V的相近。实验结果显示,本研究已成功获得一种长效重组FSH。     

促卵泡成熟激素受体与卵巢癌发生发展的关系研究进展

近年来促性腺激素及其受体与卵巢癌的关系研究受到人们的广泛关注,目前已在基础性研究和流行病学调查方面取得了巨大的进展.在体内和体外模型中都已证实,作为促性腺激素成分之一的促卵泡成熟激素通过其受体对卵巢上皮细胞的细胞增殖、凋亡、细胞粘附、侵袭和转移等生物学功能发挥了重要影响.这些研究证明了促卵泡成熟激素受体和卵巢癌的发生发展密切相关,它不但增强卵巢肿瘤细胞的增殖活性,还激活多种信号通路,促进肿瘤细胞的侵袭和转移能力;促卵泡成熟激素受体的脱敏化可能是卵巢癌发生的重要分子机制;从基因水平上,其多态性还与卵巢癌的易感性密切相关;由于它介导上皮性卵巢癌的多种恶性生物功能,因此,它是一个潜在的抗卵巢癌治疗的重要靶标.虽然如此,但是卵巢癌的发生是一个相当复杂的过程,促卵泡成熟激素及其受体在卵巢癌发病中的作用机制还不清楚.     

NK4基因转染对人卵巢癌细胞SKOV-3生物学特性的影响

目的 通过在人卵巢癌细胞SKOV-3中转染NK4基因表达片段,研究NK4对人卵巢癌的治疗作用,从而验证NK4可作为卵巢癌潜在的基因治疗新策略.方法 用NK4和荧光霉素表达质粒分别稳定转染人卵巢癌细胞SKOV-3.用West-ern blot检测细胞培养基中NK4蛋白表达,以及经不同培养基(SKOV-3、SKOV-3/LUC和SKOV-3/NK4培养上清)培养后SKOV-3细胞中c-Met和磷酸化-c-Met的表达.用MTT试剂盒绘制细胞生长曲线.用细胞划痕试验检测NK4对细胞转移的作用.结果 在SKOV-3/NK4培养基中有NK4蛋白表达,对照(SKOV-3,SKOV-3/LUC)细胞中无表达.磷酸化-c-Met在SKOV-3/NK4培养基培养的SKOV-3细胞中被抑制,而在对照(SKOV-3,SKOV-3/LUC)细胞培养基培养的SKOV-3细胞中正常表达.c-Met表达在各组差异无统计学意义.三种细胞体外生长曲线差异无统计学意义(P＞0.05).细胞划痕试验表明SKOV-3/NK4划痕区域的细胞个数明显少于SKOV-3和SKOV-3/LUC细胞.结论 NK4蛋白在SKOV-3/NK4细胞培养基中大量分泌,NK4能抑制人卵巢癌细胞c-Met受体磷酸化,并能抑制卵巢癌细胞体外活动能力,为应用NK4作为卵巢癌基因治疗方法提供了研究基础.     

卡铂通过抑制ERK1/2通路诱导人卵巢癌细胞S和G_1期阻滞

卡铂(carboplatin,CBP)是一种抗肿瘤活性较强的化疗药物,通过诱导细胞周期阻滞抑制肿瘤细胞生长,但其诱导细胞周期阻滞的报告不甚一致.本研究探索卡铂对卵巢癌HO-8910细胞生长及细胞周期进程的影响.MTS结果显示,卡铂以浓度和时间依赖方式抑制卵巢癌HO-8910细胞生长,联合使用ERK1/2通路抑制剂PD98059可使卡铂抗卵巢癌细胞增殖作用增强.采用Giemsa染色法观察到,卡铂与PD98059单用或联用均能致卵巢癌细胞发生明显的形态学变化.流式细胞术检测细胞周期发现,随卡铂浓度的增高,S期阻滞作用增强;抑制ERK1/2通路可拮抗卡铂对HO-8910细胞S期阻滞作用,增加G1期阻滞作用,而对G2/M期细胞影响不明显.Western印迹结果显示,随卡铂浓度的增高,p-ERK1/2、Cdc2(Y15)和p-Cdc2(T161)的表达逐渐升高,Cyclin E1和Cyclin B1的表达逐渐降低;抑制ERK1/2通路可将卡铂上调,p-ERK1/2和p-Cdc2(T161)的作用反转为下调作用,上调Cdc2(Y15)的表达受阻,抑制Cyclin B1的下调作用,促进Cyclin E1的下调作用.本研究结果提示,卡铂通过抑制ERK1/2激活,诱导人卵巢癌HO-8910细胞S和G1期阻滞,抑制卵巢癌细胞生长.     

LMTK2基因沉默抑制人上皮性卵巢癌细胞生长和转移的作用机制

摘要 目的：探讨狐猴酪氨酸激酶2（LMTK2）基因沉默对人上皮性卵巢癌(EOC)细胞生长和转移的抑制作用及其可能的机制。方法：通过RT-qPCR和Western-blot检测了人正常卵巢上皮细胞IOSE80和人上皮性卵巢癌细胞系（SKOV3、ES2、OVCAR-3和HEY）中LMTK2的表达,使用Lipofectamine 3000转染试剂将LMTK2的短发夹RNA（shRNA）、阴性对照shRNA、LMTK2过表达重组pcDNA3.1质粒或阴性对照质粒转染到SKOV3细胞中,并分为LMTK2-shRNA组、NC-shRNA组、LMTK2-pcDNA3.1组或NC-pcDNA3.1组。另外,使用PI3K/Akt抑制剂LY294002处理SKOV3细胞1 h。通过CCK-8法测定细胞增殖,Annexin V-FITC/PI染色法测定细胞凋亡,划痕实验评价细胞迁移,Transwell实验评价细胞侵袭。对BALB/c雌性裸鼠皮下注射转染NC-shRNA或LMTK2-shRNA的SKOV3细胞建立体内移植瘤模型,并记录接种28 d内的肿瘤体积。结果：与人正常卵巢上皮细胞IOSE80相比,卵巢癌细胞系（SKOV3、ES2、OVCAR-3和HEY）中LMTK2的mRNA和蛋白表达水平均显著升高,其中SKOV3的LMTK2 mRNA和蛋白表达水平最高（P<0.05）。与NC-shRNA组相比,LMTK2-shRNA组SKOV3细胞活力、相对迁移面积、侵袭细胞数均显著降低,而细胞凋亡率显著升高（P<0.05）。此外,与NC-shRNA组相比,LMTK2-shRNA组SKOV3细胞中Bax的蛋白表达水平显著升高,而Bcl-2、MMP2、MMP9、p-Akt的蛋白表达水平显著降低（P<0.05）。LY294002处理逆转了上调LMTK2对SKOV3细胞生长和转移的影响（P<0.05）。在接种第21天和28天时,与NC-shRNA组相比,LMTK2-shRNA组裸鼠的肿瘤体积显著降低（P<0.05）。结论：LMTK2基因沉默通过抑制PI3K/Akt信号通路降低了人上皮性卵巢癌细胞的生长和转移能力。     

PHD1通过下调NF-κB介导的cyclinD1的表达抑制肺癌细胞的生长和增殖

目的:探讨PHD1在肺癌中的功能,并进一步研究其分子机制,为肺癌的治疗寻找新的靶点。方法:选取人肺癌细胞A549,以脂质体为载体一方面过表达PHD1,另一方面合成设计靶向PHD1的siRNA沉默PHD1,利用荧光素酶检测NF-κB的活性,分别用western blot和real-time PCR检测cyclinD1的表达水平。在A549细胞中过量稳定表达带GFP标记的PHD1,流式细胞仪检测细胞周期变化,测量细胞的生长曲线,并将细胞注射到裸鼠皮下观察其成瘤情况。结果:过表达PHD1可明显抑制NF-κB的活性和IκBα的降解,降低cyclin D1的mRNA和蛋白表达水平;而干扰PHD1的表达可显著增加NF-κB的活性,并上调cyclin D1的mRNA和蛋白表达水平,而不影响cyclinE1。过表达IκBαSR可以阻止干扰PHD1引起的cyclinD1 mRNA水平的上调。过表达PHD1可引起细胞周期的停滞,显著抑制细胞的增殖和移植瘤的生长。结论:PHD1可能通过下调NF-κB介导的cyclinD1的表达抑制肺癌细胞的生长和增殖。     

BRD7调控Rb/E2F通路的分子机制研究

BRD7是采用cDNA代表性差异分析法克隆的一个新的Bromodomain基因,过表达BRD7可抑制鼻咽癌细胞的生长和细胞周期进程,同时发现BRD7基因可以调控Rb/E2F通路的活性.该研究旨在进一步探讨BRD7调控Rb/E2F通路的分子机制.通过蛋白质印迹和RT-PCR实验方法发现,BRD7能够降低Rb的磷酸化水平,抑制cyclinD1、cyclinE的蛋白质表达,上调CDK4抑制子P19的mRNA表达,但对CDK4和CDK2的蛋白质表达没有明显影响;通过荧光素酶实验从转录调控水平进一步证实了BRD7能够明显抑制cyclinD1启动子活性;采用反义核酸技术抑制COS7细胞内源性BRD7的表达后,发现cyclinD1、cyclinE、磷酸化Rb的蛋白质表达水平上调,并且可以促进细胞生长.这些结果表明:BRD7参与调控Rb/E2F信号通路中重要靶分子的表达,抑制Rb/E2F通路的活性,从而阻止细胞周期G1-S期进程,抑制鼻咽癌细胞生长.     

Solution structure of a synthetic peptide corresponding to a receptor binding region of FSH (hFSH-beta 33-53).

The receptor binding surface of human follicle-stimulating hormone (hFSH) is mimicked by synthetic peptides corresponding to the hFSH- chain amino acid sequences 33–53 [Santa-Coloma, T. A., Dattatreyamurty, D., and Reichert, L. E., Jr. (1990),Biochemistry 29, 1194–1200], 81–95 [Santa-Coloma, T. A., and Reichert, L. E., Jr. (1990),J. Biol. Chem. 265, 5037–5042], and the combined sequence (33–53)–(81–95) [Santa-Coloma, T. A., Crabb, J. W., and Reichert, L. E., Jr. (1991),Mol. Cell. Endocrinol. 78, 197–204]. These peptides have been shown to inhibit binding of hFSH to its receptor. Circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy were used to determine the structure of the first peptide in this series, the 21 amino acid peptide hFSH--(33–53), H₂N-YTRDLVYKDPARPKIQKTCTF-COOH. Analysis of CD data indicated the presence of approximately equal amounts of antiparallel -pleated sheet, turns including a -turn, other structures, and a small amount ofa-helix. The major characteristics of the structure were found to be relatively stable at acidicpH and the predominant effect of increased solvent polarity was a small increase ina-helical content. One- and two-dimensional NMR techniques were used to obtain full proton and carbon signal assignments in aqueous solution atpH 3.1. Analysis of NMR results confirmed the presence of the structural features revealed by CD analysis and provided a detailed picture of the secondary structural elements and global folding pattern in hFSH--(33–53). These features included an antiparallel -sheet (residues 38–51 and 46–48), turns within residues 41–46, and 50–52 (a -turn) and a small N-terminal helical region comprised of amino acids 34–36. One of the turns is facilitated by prolines 42 and 45. Proline-45 was constrained to thetrans conformation, whereas proline-42 favored thetrans conformer (70%) over thecis (30%). Two resonances were observed for the single alanine residue (A-43) sequentially proximal to P-42, but the rest of the structure was minimally affected by the isomerization at proline-42. The major population of molecules, containingtrans-42 andtrans-45 prolines, presented 120 NOEs. Distance geometry calculations with 140 distance constraints and energy minimization refinements were used to derive a moderately well-defined model of the peptide's structure. The hFSH--(33–53) structure has a highly polar surface composed of six cationic amino acid (arginie-35, lysine-40, arginine-44, lysine-46, glutamine-48, and lysine-49) and two anionic residues (aspartate-36 and aspartic acid-41). A hydrophobic region in the structure is composed of residues in the antiparallel -sheet and -turn which fold to produce a distorted hairpin. The structure of this domain, together with the protruding and positively charged region in the vicinity of residues 42–45, may mimic the surface of hFSH that binds to the receptor.Abreviations used: hFSH, human follicle-stimulating hormone; PB, 25 mM Na₂KPO₄, 25 mM KH₂PO₄, and 5 mM Mg Cl₂; CD, circular dichroism spectrapolarimetry; NMR, nuclear magnetic resonance spectrometry; COSY, homonuclear correlated spectroscopy; NOESY, 2D nuclear Overhauser effect spectroscopy; HOHAHA, homonuclear Hartman-Han coherence transfer; HMQCHY, reverse-detected heteronuclear multiple shift correlation, one bond; HMBC, reverse-detected heteronuclear multiple bond correlation; S/N, signal to noise ratio; TFE, trifluoroethanol.Dr. Santa-Coloma is on leave of absence from the National Research Council of Argentina (CONICET).     

Gene expression profiling of mouse Sertoli cell lines

The proliferation and differentiation of Sertoli cells is regulated by follicle-stimulating hormone (FSH). The molecular events following FSH stimulation are only partially known. To investigate FSH action in Sertoli cells, we established two novel FSH-responsive mouse Sertoli-cell-derived lines expressing human wild-type (WT) FSH receptor (FSHR) or overexpressing mutated (Asp567Gly) constitutively active FSHR (MUT). Gene expression profiling with commercially available cDNA arrays, including 588 mouse genes, revealed 146 genes expressed in both cell lines. Compared with the expression pattern of WT cells, 20 genes were identified as being either up- or down-regulated (>two-fold) in the MUT cells. We observed a strong differential expression of factors involved in cellular proliferation, e.g. cyclin D2 (repressed to nearly undetectable levels), proliferating cell nuclear antigen (2.5-fold repression) and Eps-8 (six-fold repression), and in genes involved in cellular differentiation, e.g. cytokeratin-18 (13-fold induction). The cDNA array results for six representative genes were confirmed by Northern blotting, which also included the parental SK-11 cell line devoid of FSHR expression. We found no further acute FSH- or forskolin-induced change in expression levels after 3-h stimulations, suggesting that the observed differences between the two cell lines is a consequence of mild, chronically increased, cAMP production in MUT cells. These results provide a platform for the further investigation of selected candidate genes in primary cultures and/or in vivo.Electronic Supplementary Material Supplementary material is available in the online version of this article at This work was supported by grants from the Deutsche Forschungsgemeinschaft (Confocal Research Group The Male Gamete: Production, Maturation, Function, grant FOR 197-3) and from the German Academic Exchange Service (DAAD) to P. Mathur     

Analysis of glycoprotein hormone receptor extracellular domain interactions using a solid-phase capture assay

The receptors for the glycoprotein hormones are unique in having a large extracellular domain that is responsible for mediating ligand binding. We describe the characterization, validation, and application of a solid-phase radioligand binding assay that can be used to assess the interaction of peptides and small molecules at the extracellular domain (ECD) of the follicle-stimulating hormone receptor (FSHR). The assay utilizes a C-terminal tag on the FSHR-ECD, which is used to capture the ECD and position it in a sterically favorable orientation on a solid-phase platform. Competition experiments with the cognate ligand, FSH, indicated that the interaction at the FSHR-ECD using the solid-phase assay was comparable to the full-length receptor assayed using a standard filtration assay. The utility of the assay was evaluated by competing several peptides and a small molecule for both the full-length FSHR and the FSHR-ECD. The solid-phase capture format allowed for the establishment of an assay to specifically evaluate compounds that interact at the ECD or require the full-length receptor, thereby facilitating structure-activity studies. This assay format should be applicable to the other receptors of this family.     

Effect of FSH on E2/GPR30-mediated mouse oocyte maturation in vitro

Mammalian oocyte restores meiosis can be stimulated by follicle-stimulating hormone (FSH) under normal physiological conditions. G-protein coupled receptor 30 (GPR30), an non-classical estrogen membrane receptor, has been widely reported in teleost oocyte maturation. However, it remains unknown whether GPR30 involves the role of FSH in mammalian cumulus expansion and oocyte maturation. Here, we used mouse cumulus-oocyte complexes (COCs) as a model to investigate how FSH affects the in vitro maturation of mouse oocytes mediated by 17β-estradiol (E₂)/GPR30 signaling. Our study reveals that FSH starts regulating mouse cumulus expansion precisely at 8 h in in vitro culture. ELISA measurement of E₂ levels in culture medium revealed that FSH activated aromatase to promote E₂ production in vitro in cultured mouse COCs. Moreover, the results of real-time quantitative PCR indicated that FSH-induced in vitro maturation of mouse oocytes was regulated by the estrogen-signaling pathway mediated by GPR30; FSH treatment markedly increased the mRNA expression of HAS2, PTGS2, and GREM1 in COCs. Exploration of the underlying mechanism suggested that E₂ produced by mouse COCs regulated the phosphorylation level of extracellular signal-regulated kinase 1/2 (ERK1/2) through GPR30 and thereby promoted mouse cumulus-cell expansion and oocyte maturation. In conclusion, our study reveals that FSH induced estrogen production in mouse COCs through aromatase, and that aromatase/GPR30/ERK1/2 signaling is involved in FSH-induced cumulus expansion.     

Effects of gonadotropins and granulosa cell secretions on the maturation and fertilization of rat oocytes in vitro

Fully grown germinal vesicle-stage oocytes are induced to resume meiosis and acquire the capacity to undergo fertilization in response to a surge of gonadotropins. The present study examined possible direct and indirect roles of gonadotropins in the maturation and fertilization of rat oocytes by determining 1) the effect of exogenous administration of gonadotropins (priming) to immature rats prior to oocyte collection on the capacity of oocytes to undergo maturation and fertilization in vitro, 2) the effect of follicle-stimulating hormone (FSH) in the maturation media on the resumption of meiosis and subsequent capacity of oocytes to undergo fertilization, and 3) the capacity of oocytes to undergo maturation and fertilization following culture in preovulatory follicular fluid or in conditioned media obtained from gonadotropin-stimulated granulosa cell (GC) cultures. In the first experiment, oocytes from unprimed rats underwent spontaneous meiotic maturation in vitro and 17% underwent subsequent fertilization. Priming increased the proportion of oocytes undergoing fertilization. Maturation of oocytes in media supplemented with various concentrations of FSH or for various lengths of time (6-16 h) in medium with 500 ng FSH/ml indicated that FSH slowed the rate of meiotic maturation, but had no effect on the capacity of the oocytes to be fertilized. Oocytes obtained from primed animals and cultured in the presence of preovulatory follicular fluid were fertilized in proportions similar to those cultured in serum-containing medium. In the third experiment, medium conditioned by FSH-stimulated GC for 40 h slowed the rate of meiotic maturation; the addition of luteinizing hormone (LH) to the FSH-stimulated cells produced a medium in which the rate of oocyte maturation was not different from that of control oocytes (in medium from unstimulated cells). Medium conditioned by FSH- or LH-stimulated GC, but not fibroblasts, increased the proportions of oocytes undergoing fertilization following maturation in those media. FSH + LH stimulation of GC increased the fertilization of oocytes to proportions significantly higher than with either gonadotropin alone. These data suggest that GC respond to gonadotropin stimulation by providing a factor(s) that regulates the rate of oocyte maturation and promotes the capacity of oocytes to undergo fertilization.     

Changes in circulating levels of immunoreactive follicle stimulating hormone, luteinizing hormone, and testosterone during sexual development in the rhesus monkey, Macaca mulatta

Basal serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone (T) and the responsiveness of these hormones to a challenge dose of luteinizing hormone releasing hormone (LHRH), were determined in juvenile, pubertal, and adult rhesus monkeys. The monkey gonadotrophins were analyzed using RIA reagents supplied by the World Health Organization (WHO) Special Programme of Human Reproduction. The FSH levels which were near the assay sensitivity in immature monkeys (2.4 +/- 0.8 ng/ml) showed a discernible increase in pubertal animals (6.4 +/- 1.8 ng/ml). Compared to other two age groups, the serum FSH concentration was markedly higher (16.1 +/- 1.8 ng/ml) in adults. Serum LH levels were below the detectable limits of the assay in juvenile monkeys but rose to 16.2 +/- 3.1 ng/ml in pubertal animals. When compared to pubertal animals, a two-fold increase in LH levels paralleled changes in serum LH during the three developmental stages. Response of serum gonadotrophins and T levels to a challenge dose of LHRH (2.5 micrograms; i.v.) was variable in the different age groups. The present data suggest: an asynchronous rise of FSH and LH during the pubertal period and a temporal correlation between the testicular size and FSH concentrations; the challenge dose of LHRH, which induces a significant rise in serum LH and T levels, fails to elicit an FSH response in all the three age groups; and the pubertal as compared to adult monkeys release significantly larger quantities of LH in response to exogenous LHRH.     

Factors influencing resumption of meiotic maturation and cumulus expansion of porcine oocyte-cumulus cell complexes in vitro

The present study was undertaken to examine effects of various combinations of epidermal growth factor (EGF), transforming growth factor-b?₁ (TGF-b?₁), follicle-stimulating hormone (FSH), luteinizing hormone (LH), androstenedione (A₄), and estradiol-17b? (E₂) on meiotic maturation and cumulus expansion in the pig using an in vitro model system. Oocyte-cumulus cell complexes (OCC) were cultured in the media containing the abovementioned agents for 24 hr and were observed for germinal vesicle breakdown (GVBD), indicative of initiation of meiotic maturation, and for expansion of their cumulus cells. Treatment with EGF significantly increased (P < 0.05) incidence of GVBD, with maximal stimulation occurring at 1 ng/ml (55% vs. 12% in the control). Concentrations of EGF as low as 100 pg/ml significantly stimulated GVBD over control (37% vs. 12%). Addition of EGF (1 ng/ml) and FSH (1.5 μg/ml) together and LH (2 μg/ml) and FSH (1.5 μg/ml) together resulted in significantly higher (P < 0.01) GVBD levels than were observed in response to EGF, FSH, or LH alone. Addition of E₂ (1 μg/ml) had no effect by itself but significantly decreased the incidence of GVBD in the presence of FSH and of LH + FSH. Addition of A₄ (1 μg/ml) significantly reduced the percentage of oocytes undergoing GVBD when added alone or with FSH. Although both EGF and LH stimulated cumulus expansion, FSH was more effective in stimulating cumulus expansion than EGF or LH. TGF-b?₁ had no effect on GVBD or cumulus expansion. These studies indicate that these hormones may have differing roles in oocyte maturation and that their interactions may be part of an intricate system regulating the maturation of oocytes during follicular development in vivo. © 1993 Wiley-Liss, Inc.     

Effects of gonadotropin-releasing hormone administration on the pituitary-gonadal axis in male and female dogs before and after gonadectomy

GnRH-stimulation tests were performed in 14 female and 14 male client-owned dogs of several breeds, before and 4 to 5 mo after gonadectomy. The aim of the study was to obtain more insight into the pituitary-gonadal axis in intact and neutered dogs and to establish reference values. Basal plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations were increased significantly after gonadectomy in both bitches and male dogs. In both males and females ranges of the basal plasma FSH concentrations, before and after gonadectomy, did not overlap as opposed to the overlap in ranges of the basal plasma LH concentrations. Before gonadectomy basal plasma LH concentrations were lower and basal plasma FSH concentrations were higher in bitches than in male dogs. After gonadectomy these basal values did not differ significantly. GnRH administration before gonadectomy resulted in an increase in plasma LH and FSH concentrations in both genders. GnRH administration after gonadectomy produced an increase only in plasma LH concentrations in both genders, and a just significant increase in plasma FSH in castrated male dogs. GnRH administration before gonadectomy resulted in a significant increase in plasma testosterone concentration in both genders. In males ranges of basal and GnRH-stimulated plasma testosterone concentrations before and after gonadectomy did not overlap. Basal plasma estradiol concentrations were significantly higher in intact males than in castrated males and their ranges did not overlap. The basal estradiol concentrations in bitches before and after ovariectomy were not significantly different. At 120 min after GnRH administration, ranges of plasma estradiol concentration of intact and ovariectomized bitches no longer overlapped. In conclusion, basal plasma FSH concentration appears to be more reliable than basal plasma LH concentration for verification of neuter status in both male and female dogs. The basal plasma testosterone concentration appears to be reliable for verification of neuter status in male dogs. The plasma estradiol concentration at 120 min after GnRH administration can be used to discriminate between bitches with and without functional ovarian tissue.