The influence of estradiol-17beta and progesterone on peripheral serum concentrations of luteinizing hormone and follicle stimulating hormone in the ovariectomized ewe

Serum gonadotropin concentrations were high and variable and fluctuated episodically in short and long term ovariectomized ewes. Treatment with solid silastic implants releasing progesterone (serum levels 1.81 +/- 0.16 ng/ml) had no consistent effect. Treatment with implants releasing estradiol-17beta significantly depressed mean serum gonadotropin concentrations and peak height to values usually seen in intact ewes. This occurred regardless of implant size and serum estradiol-17beta concentrations (range 11 +/- 0.3 pg/ml to 98 +/- 12.8 pg/ml). Progesterone and estradiol-17beta together significantly depressed the frequency of peaks in LH concentration. Following progesterone removal, 95% of the ewes treated with progesterone and estradiol-17beta implants experienced a transient increase in serum LH concentrations similar to the preovulatory surge in intact ewes. Eighty-four percent of the LH surges were accompanied by a surge in serum FSH concentrations. However, following progesterone removal, 5.1 +/- 2.1 FSH surges were observed over six days. Gonadotropin surges occurred regardless of estradiol-17beta implant size and with or without the influence of supplemental estradiol-17beta.     

光照对鸡生长、产蛋及血浆雌二醇、黄体生成素、甲状腺素的影响

70日龄星杂“579”小母鸡120只,随机分成A、B、C三组。C组为对照组。A、B两组分别以32和8Lx的强度补充光照,使其每天的光照时间达14h。从70日龄起,每10天称重一次;从开产日龄起,对每只鸡的产蛋分别按日龄称重、登记。结果表明,光照强度与鸡的生长速度和平均蛋重相关不显著,而与鸡的性成熟和产蛋量显著相关。用放射免疫分析法测定了三组鸡100～180日龄间外周血浆E_2、LH和T_4含量,B组鸡LH峰值最高,其峰值(149日龄)与基础值(100日龄)对比,增长率为231.4％;A组鸡血浆T_4水平增加明显,但其产蛋量相对较低;补充光照组能促使血浆E_2峰值的出现早于自然光照组,但各组鸡E_2峰值无显著差异。     

恒河猴(Macaca mulatta)生殖周期内性类固醇激素分泌规律的研究

本文用放射免疫测定法对7只雌性恒河猴(Macaca mulatta)的20个月经周期进行了雌二醇、孕酮和睾酮的动态测定分析,其中15个月经周期的中期都有睾酮和雌二醇峰(其峰值分别为1010.7±411.3pg/ml和179.1±91.3pg/ml),孕酮在黄体期的峰值为2.54±0.65ng/ml。正常黄体期的血清孕酮水平不低于1ng/ml。20个月经周期的平均天数为28.6±5.4天,滤泡期和黄体期分别为11.9±2,6和19.2±6.3天。月经周期可用公式Y=18.92±0.03×X~2 (Y:月经周期,X:黄体期。R=0.9444)表示。实验结果表明,测定周期内三种性类固醇激素可以准确确定排卵。睾酮在生殖周期内的分泌调节机制还待进一步研究。     

The effect of antiestrogens on egg yolk protein synthesis and estrogen-binding to chromatin in the rooster liver

Nafoxidine and CI-628, two well known antiestrogenic compounds, reduce the stimulating effect of estradiol on the estrogen-binding capacity of the liver chromatin from roosters. In vitro both antiestrogens compete with [³H] estradiol for the binding sites on the liver chromatin. They inhibit the estrogen-induced synthesis of egg yolk proteins (vitellogenin) and fail to induce this estrogen-specific protein synthesis by themselves. They show the ability, however, to increase the estrogen-binding sites on the liver chromatin to some extent.     

大豆异黄酮改善母鼠抑郁样行为的作用及其雌激素受体β机制*

目的:观察大豆异黄酮改善母鼠抑郁样行为的作用及其与血清雌二醇(E₂)、多巴胺(DA)及脑区雌激素受体β(ERβ)关系。方法:将产后2 d的母鼠随机分为:对照组和长期分离模型组,对照组不给予任何刺激,长期分离模型组母鼠给予每天3 h分离建立产后抑郁母鼠模型,10 d后,将造模成功的母鼠再分为:模型组、低浓度组和高浓度组,每组10只,加上对照组,共4组。模型组、低浓度组和高浓度组分别灌胃蒸馏水、15 mg/kg·d^-1和30 mg/kg·d^-1大豆异黄酮10 d,之后观察强迫游泳和悬尾实验中挣扎的时间、频次和静止的时间、频次,取血检测血清E₂和DA浓度,取脑免疫组化检测杏仁内侧核(MeA)、终纹床核(BNST)和中视前区(mPOA)ERβ的表达。结果:与对照组比较,模型组和低浓度组小鼠在强迫游泳和悬尾实验中的运动时间和频次明显降低,血清中的DA、ERβ浓度明显降低(P＜0.05或P＜0.01),模型组、低浓度和高浓度的E₂均明显降低(P＜0.01);与模型组比较,低浓度组小鼠在强迫游泳和悬尾实验中运动时间、mPOA内ERβ表达显著升高(P＜0.05),高浓度组小鼠在强迫游泳和悬尾实验中运动时间和频次、血清DA浓度和ERβ表达均明显升高(P＜0.05或P＜0.01);与低浓度组比较,高浓度组在强迫游泳和悬尾实验中运动时间和频次、血清DA浓度和ERβ表达均明显升高(P＜0.05或 P＜0.01)。结论:大豆异黄酮可减少母鼠的抑郁样行为,尤其是较高浓度大豆异黄酮减少更为明显,而抑郁样行为的减少可能与大豆异黄酮使血清多巴胺和雌激素受体β水平升高有关。     

雌孕激素对ALI大鼠α-ENaC、BNP、TNF-α表达的影响

目的:研究雌孕激素对ALI大鼠II型肺泡上皮细胞钠通道(epithelial Na+channel,ENaC)α亚基,血清脑钠肽(brain natriuretic peptide,BNP)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)表达的影响,探讨肺泡内液体清除的机制。方法:雌性未成年SD大鼠30只,随机分为3组:对照组(静脉注入生理盐水8 mL/kg)、ALI模型组(静脉注入油酸0.1 mL/kg)、雌孕激素联合组(在油酸注入前12 h、36 h皮下注射1∶1 000雌孕激素混合液0.1 mL)。建模后6 h处死大鼠,观察肺组织病理改变,测定肺湿重/干重比值、肺系数,肺组织匀浆中α-ENaC mRNA及蛋白的表达及血清BNP、TNF-α的表达。结果:与对照组比较,模型组出现明显肺水肿、出血及炎性细胞浸润,肺湿重/干重比值、肺系数及血清中BNP、TNF-α表达增加,而α-ENaC mRNA及蛋白明显降低(P<0.01);雌孕激素联合组与ALI模型组比较,肺水肿、出血及炎性细胞浸润要轻,肺湿重/干重比值、肺系数、BNP下降,α-ENaC mRNA及蛋白增加(P<0.05)。结论:雌孕激素联合治疗可上调α-ENaC mRNA及蛋白的表达,减少BNP表达,促进肺泡内液体的清除,为ALI/急性呼吸窘迫综合症(ARDS)的治疗和监控提供新的方法。     

Suppression of ovulation by a synthetic progestin in the capuchin monkey

Background  From the limited research in New World monkeys it is not clear whether they are as sensitive to the antiovulatory effects of synthetic progestins as noted in human beings. We examined whether levonorgestrel prevented ovulation in the capuchin monkey.
Methods  Cebus apella monkeys were treated orally with two doses of 2 mg of levonorgestrel, 8–9 hours apart, in four periovulatory stages assessed by laparoscopy.
Results  Levonorgestrel-induced luteinization of the follicle prevented oocyte release up to 8 hours before ovulation. Unhealthy oocytes were recovered from 46% of unruptured follicles. Luteal progesterone was reduced by 55%, 35%, and 25% according to when levonorgestrel was given −2, −1, and 0 day from estradiol peak respectively.
Conclusion  The capuchin monkey, a neotropical primate in which progesterone circulates at levels much higher than in Old World primates and human beings, is sensitive to the antiovulatory effects of synthetic progestins.     

Comparative effects of interferon alpha‐2b and pegylated interferon alpha‐2b on menstrual cycles and ovarian hormones in cynomolgus monkeys

BACKGROUND : The covalent modification of interferon (IFN) α2b with monomethyoxy polyethylene glycol (PEG) reduces its clearance rate and increases its half‐life. High doses of interferon (IFN) α2b have previously been shown to affect maintenance of pregnancy in rhesus monkeys. Given the role of ovarian hormones in reproductive function and pregnancy, this study was conducted to assess the effects of PEG‐IFNα2b or IFNα2b (comparative control) on ovarian hormones and menstrual cyclicity in cynomolgus monkeys. In addition, the potential for reversibility of PEG‐IFNα2b or IFNα2b‐related observations was assessed. METHODS : Monkeys were administered 3,105 µg/m² human recombinant (hr) IFNα2b or 52, 262, or 4,239 µg/m² PEG‐hr‐IFNα2b every other day for one menstrual cycle, followed by a post‐dose period of up to two menstrual cycles. RESULTS : Monkeys administered 3,105 µg/m² hr‐IFNα2b or 52, 262, or 4,239 µg/m² PEG‐hr‐IFNα2b exhibited transient decreases in food consumption, leukocyte and erythrocyte parameters. Monkeys administered 3,105 µg/m² hr‐IFNα2b exhibited lengthened menstrual cycles that were associated with a delay in reaching peak ovarian hormone levels and lower respective peak concentrations. Similarly, monkeys administered 4,239 µg/m² PEG‐hr‐IFNα2b exhibited lengthened menstrual cycles and a delay in reaching peak ovarian hormone levels and slightly lower respective peak concentrations. Post‐dosing menstrual cycle length, estradiol and progesterone profiles exhibited evidence of recovery in both the hr‐IFNα2b and the high‐dose PEG‐hr‐IFNα2b groups. CONCLUSIONS : Administration of hr‐IFNα2b or PEG‐hr‐IFNα2b at high doses to cynomolgus monkeys resulted in similar effects on menstrual cycles, estradiol and progesterone profiles, and exhibited evidence of reversibility upon cessation of dosing. These results suggest that the previously observed high‐dose IFNα‐related effects on the maintenance of pregnancy in monkeys are likely the result of altered ovarian function. Birth Defects Res (Part B) 86:29‐39, 2009. © 2009 Wiley‐Liss, Inc.