共查询到19条相似文献，搜索用时 170 毫秒
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褪黑素(MLT)是松果体分泌的一种神经内分泌激素,具有参与免疫反应、调节生命活动的节律性等多种生物学功能,并与生殖内分泌息息相关。目前对于褪黑素的研究主要集中在人类的癌症和植物等方面,而关于动物生殖内分泌的研究较少,深度较浅。研究表明,褪黑素可以调控动物下丘脑-垂体-性腺轴生殖相关激素的内分泌作用,抑制或促进促性腺激素释放激素(GnRH)、促卵泡素(FSH)、促黄体素(LH)、性腺激素的分泌。而在不同物种间,褪黑素作用效果却不同。论文综述了褪黑素对促性腺激素释放激素、促卵泡素、促黄体素、性腺激素以及其他与生殖相关激素的调控,为褪黑素调控动物生殖内分泌的的研究提供参考,以期对褪黑素在动物生殖调控中的作用更深入了解。 相似文献
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植物甾醇的类雌激素功能及其对动物生殖发育的影响 总被引：1，自引：0，他引：1
植物甾醇是一种新型饲料添加剂,具有多种生物学功能,如类雌激素功能、影响胆固醇代谢、抗氧化作用、抗癌作用、免疫调节功能、抗炎作用以及调节生长作用等,近年来随着植物甾醇在动物生产中的应用,其类雌激素功能及其对动物生长发育的调节作用引起了人们的广泛关注,本文简述了植物甾醇的性质和来源,对植物甾醇的类雌激素功能及其对动物生殖发育影响进行综述。 相似文献
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大量资料表明,在人类生产和生活过程中所产生的多种能模拟或颉颃体内天然激素生理作用的外源化合物会被释放到环境中,并在环境中持久存在;还会通过直接或间接的方式在动物体内蓄积、富集,与体内激素受体结合,具有模拟和干扰动物及人类内分泌功能物质的作用,从而引起人类及多种生物的神经系统失调、内分泌紊乱、免疫能力下降和生殖异常;还具有发育毒性、胚胎毒性以及致畸、致癌及引发肿瘤和免疫抑制疾病作用,这类化合物统称为"内分泌干扰物".由于内分泌干扰物是由外部环境进入机体,并产生类似内激素的作用,干扰机体内分泌系统,影响生物的生存和繁衍,也称为"环境雌激素".对环境雌激素雄性生殖毒性的作用机制进行了综述. 相似文献
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近年来,菟丝子在临床上经常用于治疗生殖内分泌类疾病,且作用效果显著。菟丝子是旋花科植物,具有毒副作用小、无耐药性、富含多种营养物质、成本低廉等优点,是纯天然的药用植物。菟丝子总黄酮是菟丝子中最有效的成分,具有止泻、滋补肝肾、益精壮阳和安胎等功效,不仅对雌雄动物生殖内分泌活动有调节作用,还对免疫、心脑血管等多个系统具有药理作用。动物的生殖内分泌活动主要由下丘脑-垂体-性腺轴调控,包括生殖激素的分泌以及精子的发生、卵泡的发育,对动物生殖繁育起着重要作用。绝大多数动物的生殖内分泌疾病都与下丘脑-垂体-性腺轴所调节的生殖激素以及生殖器官的发育状态有关,生殖激素可以通过直接或间接作用引起下丘脑-垂体-性腺轴功能性障碍疾病。鉴于目前经济动物禁用激素类药物,因此迫切需要研究安全有效低毒的中草药的作用及其机理,为其广泛应用奠定基础。文章介绍了菟丝子总黄酮主要的药理作用,并详细阐述了菟丝子总黄酮对下丘脑-垂体-性腺轴不同级内分泌活动的调控作用,为今后进一步研究菟丝子总黄酮对下丘脑-垂体-性腺轴调控的作用靶点和作用机理提供参考。 相似文献
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镉(Cd)是一种公认的对动物健康有害的金属元素。研究表明,镉中毒可引起家畜及人发生呼吸机能不全、运动失调、贫血、心血管疾病、骨质疏松、免疫力低下及癌症等多种疾病,甚至会出现急性中毒死亡,并且还具有明显的生殖内分泌干扰作用。镉作为高度可疑的具有雌激素样作用的物质已越来越受到人 相似文献
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玉米赤霉烯酮的生殖毒性研究进展 总被引：2，自引：0，他引：2
玉米赤霉烯酮是一种特殊毒性的生物毒素,它的强雌激素样作用对动物机体的伤害很大,不仅引起动物流产、死胎、低产仔率等生殖机能异常,还可以导致繁殖功能下降、不育、畸形等.已有研究表明,ZEA对肝脏、肾脏、生殖系统和免疫系统产生明显的损伤,对细胞和遗传性也有毒性作用.目前,虽然国内外学者做了大量的研究,来揭示玉米赤霉烯酮损害机体生殖功能的机制,但关于它影响机体的生殖性能更详尽的机制还亟待进一步的研究.文章主要针对玉米赤霉烯酮的生殖毒性进行了综述,总结出ZEA对生殖系统的毒性机制,从而为临床预防及治疗繁殖疾病提供理论依据. 相似文献
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异黄酮植物雌激素对雌性动物生殖、泌乳和产蛋的影响及其作用机制探讨 总被引：14，自引：6，他引：14
异黄酮植物雌激素是主要存在于豆科牧草和大豆的异黄酮类化合物,有雌激素样活性(约为17β-E2的10-3~10-5),对抗癌、抗氧化,改善心血管机能等有良好的作用。对雌性动物的生殖、泌乳和产蛋的效应,视使用剂量、持续时间和动物所处的生理状态,而呈现正负双向作用。异黄酮植物雌激素(本文涉及芒柄花素、大豆黄酮和染料木素)可与机体的E2受体竞争性结合,通过神经内分泌系统的下丘脑-垂体-性腺轴调控生殖、泌乳和产蛋机能,并在生长轴、甲状腺轴等参与下,促使相关代谢激素参与其营养过程。异黄酮植物雌激素作为生理调节剂,在饲料工业中有良好的应用前景,但必须谨慎,应通过进一步的生产试验和观察。 相似文献
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大豆是人类膳食和畜禽饲粮中的主要蛋白质来源之一,其中富含大豆异黄酮等生物活性物质。近年来的研究表明,大豆异黄酮具有与哺乳动物内源性雌激素相似的化学结构,能与机体内的雌激素受体结合,发挥类雌激素作用和抗雌激素样作用。大豆异黄酮是否对雌性动物生殖系统产生促进作用,目前仍存在争议。本文从雌性动物生殖器官形态结构、发情周期和卵巢发育、生殖激素和繁殖性能等方面,系统综述和全面分析大豆异黄酮对雌性动物生殖系统的影响,为畜牧业中科学合理利用大豆异黄酮来提高畜禽的生殖性状提供科学依据。 相似文献
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Słomczyńska M 《Polish journal of veterinary sciences》2004,7(3):223-226
Environmental estrogens may be derived from plants (phytoestrogens), pharmaceuticals or synthetic compounds. They exert estrogenic and/or potentially antiestrogenic effects on farm animals, wildlife and humans. Exposure to these compounds results in some abnormalities in the reproductive tract, changes in the estrous cycle, and possibly protection against the development of hormone-dependent cancer. The data obtained from animal studies suggest that the timing of exposure to phytoestrogens is important, and neonatal exposure causes the most pronounced effects. 相似文献
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豆科牧草的植物雌激素含量及其影响因素 总被引：2，自引：0，他引：2
豆科牧草尤其是三叶草属和紫花苜蓿含有丰富的植物雌激素.植物雌激素因化学结构与动物雌激素相似而发挥雌激素和抗雌激素的生物学功能.在畜牧生产中,适量的植物雌激素具有促进家畜生长以及提高机体免疫能力等作用,但家畜采食过多,则会引起家畜特别是反刍家畜繁殖功能的紊乱.然而,豆科牧草的植物雌激素含量在植物生育期变化幅度大,且受到许多因素影响,如植物、生态和栽培管理等,这些因素可能提高或降低豆科牧草的植物雌激素含量,因此了解这些因素对豆科牧草植物雌激素含量的影响,可以在畜牧生产中利用植物雌激素有利的作用和避免不利的作用。 相似文献
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豆科牧草尤其是三叶草属和紫花苜蓿含有丰富的植物雌激素。植物雌激素因化学结构与动物雌激素相似而发挥雌激素和抗雌激素的生物学功能。在畜牧生产中,适量的植物雌激素具有促进家畜生长以及提高机体免疫能力等作用,但家畜采食过多,则会引起家畜特别是反刍家畜繁殖功能的紊乱。然而,豆科牧草的植物雌激素含量在植物生育期变化幅度大,且受到许多因素影响,如植物、生态和栽培管理等,这些因素可能提高或降低豆科牧草的植物雌激素含量,因此了解这些因素对豆科牧草植物雌激素含量的影响,可以在畜牧生产中利用植物雌激素有利的作用和避免不利的作用。 相似文献
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Magnusson U 《Domestic animal endocrinology》2005,29(2):430-435
The phenomenon of endocrine disruption can be regarded as part of the disciplines of toxicology and environmental toxicology. These two disciplines have generated guideline protocols on how various effects of chemicals should be tested as a basis for regulatory decisions. These protocols almost exclusively involve laboratory rodents and the data obtained are then used for human risk assessment. Would it be justifiable, then, to introduce or promote the use of other species in these test protocols? There are, at any rate rationales for studying effects in species other than laboratory rodents: (1) other species may better mimic the human system; (2) they may in some cases be more useful for studying a certain mechanism or phenomenon; (3) they may highlight the diversity of effects or sensitivity between species. However, there are at least two basic criteria that must be met for a species before it can be introduced in this context: (a) we must have a good understanding of the physiological system to be studied; and (b) we must have a number of tools to study effects on this system. When it comes to the reproductive system – regarding which most endocrine disruption has been reported – farm animals are second only, or in some respects superior, to laboratory rodents with respect to these criteria. This review gives examples of how farm animals can be of use in the study of endocrine disruption with a focus on the author's own data from studies in the pig. 相似文献
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This Euroconference was a follow-up to the Euroconference held in Halle, April 1997. The programme of the conference in Halle had an exploratory character with respect to accumulation of endocrine disrupting compounds (EDCs) in the environment and in animal tissues and their effects on animal physiology and reproduction. Many questions arose from the first Euroconference, such as: What are biologically meaningful levels of environmental contamination? Is there a risk for farm animals’ health and reproduction? What assays are available and which are the most appropriate to be used? These questions formed the basis for the programme of the second Euroconference held in Wageningen in November 1998. Taking these questions into consideration, the programme of the Wageningen Euroconference was divided into four main topics. In the first session an overview was given on sources and levels of EDCs in the environment. The second session addressed chemical nature and metabolism of EDCs including phytoestrogens. In the third session the effects of EDCs on ovarian function and embryo development were discussed and in the last session the advantages and disadvantages of different in vivo as well as in vitro assays were debated. 相似文献
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生长激素(growth hormone,GH)是由脑垂体前叶分泌的一种多肽激素,它作为一种特殊的生物活性蛋白促进机体合成代谢和蛋白质合成。GH传统的作用机制是垂体产生GH开始作用于膜受体,然后刺激肝脏胰岛素生长因子(insulin-like growth factor-1,IGF-1)生成,进而影响机体多个器官发育。近年的研究表明,GH除了内分泌作用途径,还可通过自分泌及旁分泌途径产生生物学效应。GH自分泌可以参与调控雄性和雌性动物生殖功能;GH自分泌对肌肉组织的代谢和生长也有重要影响,另外,GH自分泌与肿瘤的发生有密切的关系,其在一定程度上可以促进部分癌细胞的增殖,分化与迁移。通过对GH自分泌作用机制的研究有望发现自分泌GH在动物体内新的生物学作用,也有助于研究并治疗GH自分泌异常引发的相关疾病。 相似文献
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U Magnusson 《Reproduction in domestic animals = Zuchthygiene》2012,47(Z4):333-337
In this review, possible comparative advantages of studying endocrine disruption in farm animals vs laboratory rodents are discussed. First, using farm animals, the generality of findings in laboratory rodents are challenged. Farm animals may in certain aspects be better models for humans than laboratory rodents, and sometimes there might be methodological advantages in using farm animals. Second, there are several in vitro studies based on cell-culture systems from sows and cows where the effects of chemicals on sex steroid secretion can be measured and maturation and fertilization of oocytes may be assessed. These in vitro systems are powerful tools for dissecting the mechanisms of action for endocrine-disrupting chemicals. Third, in a set of recent in vivo studies using sheep, goats and pigs, in which very different exposure regimens to endocrine-disrupting chemicals have been used, a full panel of reproductive parameters pertinent to farm animals were assessed. Clinically, it is suggested that endocrine disruption in farm animals should be considered when impaired reproduction could be linked to change in source of feed or pasture. Finally, epigenetic and toxicogenomic approaches can be particularly rewarding in elucidating endocrine disruption in future farm animal studies. 相似文献
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It is generally agreed that stress can impair reproduction. Furthermore, it is often thought that cortisol, which is secreted during stress as a result of activation of the hypothalamo-pituitary adrenal axis, is associated with this stress-induced impairment of reproduction. It has been hypothesized that reproduction in females is particularly susceptible to disruption by acute stress during the series of endocrine events that induce estrus and ovulation. Nevertheless, we found no support for this conjecture when we subjected female pigs to repeated acute stress or repeated acute elevation of cortisol during the period leading up to estrus and ovulation. Conversely, studies have demonstrated that prolonged stress and sustained elevation of cortisol can disrupt reproductive processes in female pigs. Nevertheless, in each study that demonstrated this effect, there were some animals subjected to the prolonged stressor or the sustained elevation of cortisol in which the reproductive parameters that were measured were not affected by the treatment. We propose that reproduction in female pigs is resistant to the effects of acute or repeated acute stress or acute or repeated acute elevation of cortisol even if these occur during the series of endocrine events that induce estrus and ovulation. Furthermore, while reproductive processes in some individuals are compromised, reproduction in a proportion of female pigs appears to be resistant to the effects of prolonged stress or sustained elevation of cortisol. 相似文献