妇科性激素调节机制

女性性激素主要由卵巢分泌 ,包括雌激素、孕激素及少量的雄激素。随着人们对卵巢功能调节的认识不断加深 ,传统的下丘脑 -垂体 -卵巢轴分泌的促性腺激素已不再是周期性性激素分泌的唯一调节因素 ,在卵巢局部还存在一个多因子调节网络 ,以旁分泌自分泌方式参与卵巢周期性激素合成分泌 ,并通过对促性腺激素及受体的调控 ,影响其对卵巢的作用。1　性激素的合成卵巢性激素生物合成的原料为具有 2 7个碳原子的胆固醇 ,在卵巢内经 2 0羟化酶 ,2 0、2 2裂解酶的作用下生成2 1碳孕烯醇酮 ,然后在卵泡膜细胞内通过△4 途径首先合成孕酮→ 17α羟孕酮…     

血清抑制素B对女性生殖功能的临床诊断价值

抑制素B是转化生长因子β蛋白超家族的成员之一,由窦前卵泡及早期窦卵泡分泌,特异性作用于腺垂体反馈性抑制卵泡刺激素的分泌。因其直接参与卵泡生成发育的调控,血清抑制素B是反映多种女性生殖疾病的重要指标,对于卵巢早衰、卵巢储备功能降低、多囊卵巢综合征、子宫内膜异位症、生殖系统肿瘤的诊断和治疗都有临床指导意义。     

生殖周期及内分泌调节

月经为生殖功能成熟的外在表现,呈周期性。每一月经周期,卵巢中卵子成熟,具有生殖能力。为此,月经周期又称生殖周期。生殖周期中卵巢的变化由下丘脑－垂体－卵巢分泌的生殖激素所调节,既往称女性内分泌,近年已明确主要为调节生殖功能,故称生殖内分泌。生殖周期中核心事件发生在卵巢,即卵巢在下丘脑—垂体—卵巢分泌的生殖激素的相互作用下,卵泡启动、生长,卵子成熟、排卵,卵子排出后的卵泡成为黄体。每一月经周期中可分为卵泡期、排卵期和黄体期３个时期。黄体分泌的激素供给妊娠的需要,若受孕则妊娠继续,月经闭止;若未受孕黄…     

卵泡液促血管生成因子在卵泡发育中的作用的研究进展

卵泡液由血浆渗出物和卵巢局部分泌物构成,卵泡液不仅为卵母细胞和卵巢颗粒细胞的生存提供适宜的生物环境,并且对卵泡发育、卵母细胞成熟起着直接调控作用。卵泡液中存在大量的细胞因子,它们都通过各自特有的机制作用于女性生殖过程,且随着辅助生殖技术的不断发展,卵泡液中各种细胞因子在女性生殖系统的作用逐渐被重视。本文以近年来生殖医学领域对卵泡液微环境的研究为基础,结合血管生成的机制和卵泡液中参与血管生成过程的各种细胞因子对女性生殖过程的调节,综述了卵泡液中血管生成相关因子在卵泡发育、卵子成熟及胚胎种植等女性生殖过程中的作用。     

Kisspeptin对女性生殖功能调控机制的研究进展

在女性生殖活动中,kisspeptin参与调控下丘脑-垂体-性腺(HPG)轴的功能,并通过介导雌激素的正负反馈调节促性腺激素释放激素(Gn RH)的分泌,解除促性腺激素抑制激素(Gn IH)对HPG轴的负性调控作用,继而调节促性腺激素(Gn)的分泌及类固醇甾体激素的分泌,并与多种卵巢功能异常疾病的病理过程密切相关。Kisspeptin可调控卵泡发育和排卵发生,并影响子宫内膜容受性的形成。此外,在辅助生殖技术(ART)过程中kisspeptin可代替传统h CG扳机,并降低接受ART治疗的不孕症女性卵巢过度刺激综合征(OHSS)的发生。     

年轻恶性肿瘤患者卵巢功能保护的现状及进展

在中国,年轻人群中恶性肿瘤的发生率呈逐年上升态势。10%的恶性肿瘤发生于<45岁的女性中[1]。在育龄期女性中,最常见的恶性肿瘤有乳腺癌、黑色素瘤、子宫颈癌、非霍奇金淋巴瘤及白血病,其5年生存率分别为90%、91%、71%、69%和55%[2]。卵巢是女性最重要的性腺器官,具有生殖和内分泌两大功能。卵巢分泌的激素主要为雌激素、孕激素和雄激素,不仅在维持女性性征、身体发育和性欲等方面发挥重要作用,而且参与机体的血管神经功能和水钠平衡的调节,调控脂代谢和骨代谢等。故对于女性恶性肿瘤患者在根治疾病的同时保留卵巢的生殖及内分泌功能尤其重要。     

促性腺激素作用与卵巢内调控

促性腺激素作用与卵巢内调控林金芳郑怀美垂体促性腺激素是卵巢功能的内分泌调节激素。近年来，分子生物学研究揭示了卵巢局部产生众多的肽类物质并参与垂体促性腺激素对性腺的调节作用。这些物质通过对分泌细胞本身或邻近细胞发挥作用，形成卵巢内自分泌、旁分泌调节系统...     

微小RNA在女性生殖调节中的研究进展

微小RNA(miRNA)是含有19~22个核苷酸序列的短链非编码RNA,调控内源性基因的转录后表达。随着miRNA在生殖领域不断被发现,miRNA作为女性生殖系统的重要调控因子越来越受到关注。miRNA通过调节靶基因的转录后水平,调控卵巢颗粒细胞的增殖、分化和凋亡并参与控制类固醇激素的分泌。卵巢功能异常,如多囊卵巢综合征(PCOS)和卵巢早衰(POF)均会发生miRNA调控异常。除此之外,miRNA还通过调节目标基因的表达决定胚胎的整倍体性及胚胎发育的命运。miRNA对于维持子宫内膜容受性非常重要,miRNA的异常表达会导致子宫内膜种植窗的偏移,从而导致胚胎种植失败。对miRNA在生殖调节中作用的了解,有助于发现新的预测体外受精成功率的生物指标和靶向治疗的位点,进一步提高辅助生殖的有效性和安全性。     

妇科肿瘤与激素

妇女的一生 ,由于丘脑、丘脑旁、垂体及卵巢所分泌的一系列激素的调控 ,形成女性生殖系统周期性变化的特点 ,这些与性及生殖功能调节有关的激素又称为“女性生殖激素”。其中有些与妇科肿瘤发生、发展、诊断、甚至治疗有关 ,本文将对这部分激素进行讨论。1　几种主要女性生殖激素的来源按激素的分子构成 ,将其分为二大类 :肽类激素与甾体类激素。前者包括丘脑下特殊分化细胞分泌的促性腺激素释放激素 (ＧｎＲＨ ) ,因其主要功能为刺激垂体合成与释放促黄体生成素 ,故又被称为促黄体激素释放激素 (ＬＨＲＨ)。垂体分泌的肽类促性腺激素包括卵…     

β—内啡肽在女性生殖内分泌中的调节作用

近年研究表明，β－内啡肽是调节ＧｎＲＨ分泌及月经周期的一种重要神经肽，在女性生殖不同阶段如青春期，月经周期及更年期具有不同的生理作用，在几种分泌疾病如多囊卵巢综合征，下丘脑月经失调，经前期综合征中发生明显的病理变化。     

Male reproductive proteins and reproductive outcomes

Male reproductive proteins (MRPs), associated with sperm and semen, are the moieties responsible for carrying male genes into the next generation. Evolutionary biologists have focused on their capacity to control conception. Immunologists have shown that MRPs cause female genital tract inflammation as preparatory for embryo implantation and placentation. These observations argue that MRPs are critically important to reproductive success. Yet the impact of male reproductive proteins on obstetrical outcomes in women is largely unstudied. Epidemiologic and clinical observations suggest that shorter-duration exposure to MRPs prior to conception may elevate the risk for preeclampsia. A limited literature has also linked sexual behavior to bacterial vaginosis and preterm birth. We offer a clinical opinion that MRPs may have broad implications for successful reproduction, potentially involved in the composition of vaginal microflora, risks of preterm birth and preeclampsia, and success of assisted reproduction.     

From reproductive choice to reproductive justice

Since the 1994 Cairo Conference on Population and Development, the human rights movement has embraced the concept of reproductive rights. These are often pursued, however, by means to which objection is taken. Some conservative political and religious forces continue to resist implementation of several means of protecting and advancing reproductive rights. Individuals' rights to grant and to deny consent to medical procedures affecting their reproductive health and confidentiality have been progressively advanced. However, access to contraceptive services, while not necessarily opposed, is unjustifiably obstructed in some settings. Rights to lawful abortion have been considerably liberalized by legislative and judicial decisions, although resistance remains. Courts are increasingly requiring that lawful services be accommodated under transparent conditions of access and of legal protection. The conflict between rights of resort to lawful reproductive health services and to conscientious objection to participation is resolved by legal duties to refer patients to non-objecting providers.     

Prolactin and reproductive medicine

PURPOSE OF REVIEW: This review aims to summarize current knowledge about prolactin, and outlines recent information that affects the management of patients with hyperprolactinaemia. RECENT FINDINGS: The actions of prolactin have been clarified by studies of prolactin-receptor-deficient mice, which have a clear phenotype of reproductive failure at multiple sites. The treatment of patients with hyperprolactinaemia or prolactinoma is largely achieved using dopamine agonist drugs, which induce the shrinkage of pituitary prolactinomas as well as control of the endocrine syndrome. Recent findings indicate that successful cabergoline treatment may be able to induce long-term remission, allowing drug withdrawal in a substantial proportion of patients. SUMMARY: At present, dopamine agonist drugs remain the best treatment for hyperprolactinaemic patients, and can help most affected women achieve pregnancy. Future work is likely to help understand the basis of long-term remission in patients with pituitary prolactinomas.     

Phytoestrogens and reproductive biology

Phytoestrogens are naturally occurring plant substances that can either mimic or antagonize the action of endogenous estrogens. This is because of the similarity of the functional structure of phytoestrogens and endogenous estrogens. In premenopausal women, phytoestrogen intake might induce a decrease in luteinizing hormone, follicle-stimulating hormone and estradiol (E₂), which are associated with a longer follicular phase. The circulating transport protein, sex hormone-binding globulin, is increased, resulting in less cellular availability of E₂. Phytoestrogens inhibit the activities of E₂ synthetic enzymes through adenylate cyclase and tyrosine kinase cascades. This might decrease of risk of hormone dependent cancers. A phytoestrogen-rich diet might reproduce normal body composition, affecting the course of polycystic ovary syndrome (PCOS). Some herbs used in traditional Japanese medicine contain phytoestrogens that influence endogenous hormone levels to directly regulate the pituitary-ovarian system, in particular, the chemotactic effects on ovaries. (Reprod Med Biol 2005; 4 : 225 –229)     

AIDS and reproductive health

Over 24 million adults worldwide have been infected with HIV. Primarily a sexually transmitted disease, AIDS is inexorably linked to reproductive health and care. Because HIV tends to infect those who are in their reproductive years, the impact of this disease on population growth and life expectancy is projected to be immense in some parts of the world, especially in sub-Saharan Africa. Not least is the challenge to individual families and infant care programs to care for AIDS babies. Estimates of the rate of vertical transmission of HIV range from < 10 to 46%. Transmission through sexual contact accounts for 75-85% of HIV infection worldwide, and today, nearly 20 years into the epidemic, the main tool to stall the spread is advocating change in sexual conduct. Numerous studies leave no doubt that the attributable risk of co-infection with other STDs--both ulcerative and non-ulcerative--in heterosexual transmission is substantial. The only known contraceptive method proven to reduce both infectiousness and susceptibility to HIV is barrier contraception. Spermicidal agents currently available have not been shown to reduce HIV concentrations in genital secretions, or to reduce transmission of the virus. The challenges that lie ahead are tremendous: we must continue to focus on development of affordable preventive measures; urge policy-makers to back further research in prevention to complement condom use; and advocate for continued support of basic research to learn more about fundamental mechanisms of HIV transmission.     

Aspirin and reproductive outcomes

In the late 1980s and early 1990s, researchers hypothesized that aspirin could be used to prevent or delay the onset of preeclampsia. This hypothesis was tested in numerous trials which showed limited, but positive results. Subsequently, aspirin has been used in an attempt to improve pregnancy outcomes in women who have both antiphospholipid antibodies and a history of recurrent loss, and has also been used in an attempt to improve the success of in vitro fertilization. In theory, aspirin has both positive and negative effects on reproduction. Aspirin, which suppresses cyclooxygenase, has the potential to interfere with implantation, but also has the potential to support the maintenance of pregnancy. Aspirin is prescribed with increasing frequency to reduce the risk of maternal thrombosis and reduce the risk of miscarriage and poor pregnancy outcome. Aspirin alone, however, is not considered sufficient to prevent thrombosis and even in women with the antiphospholipid syndrome, the question as to whether low-dose aspirin improves pregnancy outcomes has not been answered affirmatively. Aspirin has potential risks. Aspirin inhibits platelet function and can contribute to maternal and fetal bleeding. Aspirin crosses the placenta. Although aspirin has not been associated with other congenital anomalies, it has been associated with an increased risk of vascular disruptions, particularly gastroschisis and possibly premature closure of the ductus arteriosus. Nonetheless, large trials demonstrate low-dose aspirin's relative safety and generally positive effects on reproductive outcomes.