Effects of L-Arginine and α / 中国医学科学院学报

Kidney is one of the important organs of the body.With both excretory and endocrine functions,it plays a vital role in regulating the normal physiological state.As a precursor of the nitric oxide(NO)synthesis

Roles of Hypothalamic-Pituitary-Adrenal Axis and Hypothalamus-Pituitary-Ovary Axis in the Abnormal Endocrine Functions in Patients with Polycystic Ovary Syndrome / 中国医学科学院学报

Polycystic ovary syndrome(PCOS) is a common reproductive endocrine disease in women of childbearing age. While it can be affected by a variety of factors,its pathophysiology remains unclear. Its clinical features mainly include anovulation,hyperandrogenism,and hyperinsulinemia,which are closely related with abnormal neuroendocrine system. Hypothalamic-pituitary-gonadal axis(HPG) plays a crucial regulatory role in various life activities in mammals. In particular,hypothalamic-pituitary-adrenal(HPA) axis and hypothalamus-pituitary-ovary(HPO) axis can be abnormal in PCOS patients. The corresponding abnormalities include abnormal gonadotropin releasing hormone pulse frequency,increased luteinizing hormone/follicle-stimulating hormone ratio,and excessive excretion of adrenal and ovarian androgens. Meanwhile,insulin and leptin also play key roles in endocrine dysfunction in PCOS patients. This article systematically reviews the role of HPA axis and HPO axis in the neuroendocrine dysfunction in PCOS patients.

Histone modifications during spermatogenesis and male infertility / 中国医学科学院学报

Many pathological phenomena of male infertility are related to epigenetic changes in male germ cells. Epigenetic regulation during spermatogenesis plays an important role in mitotic/meiotic divisions and spermiogenesis. The histones have various post-translational modifications on different amino acid residues during spermatogenesis. These modifications are crucial to the precise regulation of spermatogenesis. Moreover, the histone-to-protamine transition will occur during spermiogenesis. Many studies have also found that abnormal changes of histone modifications during spermatogenesis may damage the sperm development, leading to male sterility. This article reviews the changes of histone modifications during spermatogenesis, the regulation of the development of male germ cells, and the relationship between histone abnormalities and male sterility.

Effects of bisphenol A on the female reproductive organs and their mechanisms / 中国医学科学院学报

Bisphenol A (BPA) is a commonly used phenolic environmental estrogen. Long-term exposure of female mammalians to BPA can lead to endocrine disorders, followed by the morphological and functional changes in ovary, uterus, vagina, and oviducts. The interactions of BPA with various target molecules or tissues will cause different effects. To further elucidate the effects of BPA on female reproductive system, we review the changes in the structure and functions of female reproduction system after BPA exposure and their possible mechanisms.

Effects of phosphatidylinositol-3 kinase/protein kinase b/bone morphogenetic protein-15 pathway on the follicular development in the mammalian ovary / 中国医学科学院学报

In mammals, ovarian follicle is made of an oocyte with its surrounding granulosa cells and theca cells. Follicular growth and development is a highly coordinated programmable process, which guarantees the normal oocyte maturation and makes it having the fertilizing capacity. The paracrine and autocrine between oocytes and granulosa cells are essential for the follicular development to provide a suitable microenvironment. Phosphatidylinositol-3 kinase /protein kinase B is one of these important regulatory signaling pathways during this developmental process, and bone morphogenetic protein-15 an oocyte-specific secreted signal molecule, which regulates the follicular development by paracrine in the mammalian ovary. The present article overviewed the role of phosphatidylinositol-3 kinase / protein kinase B signaling during the follicular development based on our previous investigation about protein kinase B /forkhead transcription factor forkhead family of transcription factors -3a, and then focused on the regulatory effects of bone morphogenetic protein-15, as a downstream signal molecule of phosphatidylinositol-3 kinase / forkhead family of transcription factors -3a pathway, on ovarian follicular development, which helped to further understand the molecular mechanism regulating the follicular development and to treat ovarian diseases like infertility.

Polycomb group proteins and their roles in regulating stem cell development / 中国医学科学院学报

Polycomb group (PcG) proteins are a family of epigenetic regulators responsible for the repression of genes in proliferation and differentiation of stem cells. PcG protein complex consists of two important epigenetic regulators: PRC1 (polycomb repressive complex 1) and PRC2 (polycomb repressive complex 2). In order to further understand the functions of PcG proteins in stem cell growth and differentiation, we review the PcG protein composition, PcG protein localization in the target gene, PcG protein recruitment, and the functions of PcG proteins in the development of stem cells.

Oral acrylamide affects the development and reproductive performance of male rats / 中华男科学杂志

<p><b>OBJECTIVE</b>The content of acrylamide increases remarkably in fried, baked and heat-processed starchy foods. The present experiment was aimed at investigating the toxicity of acrylamide on the reproductive system in male rats.</p><p><b>METHODS</b>Thirty weaned 21-day-old SD male rats were randomly allotted into three groups of 10 each. Group I and Group II were fed on water solutions containing acrylamide 5 mg/kg/d and 10 mg/kg/d for eight consecutive weeks, while the third group on fresh water only as the control. The body weight, viscera weights and testicle and epididymis tissues were detected at the fourth and eighth week respectively. In the end of the experiment, the sperm reserve and morphology in the cauda of the epididymis were examined.</p><p><b>RESULTS</b>The growth of the rats treated with acrylamide was retarded (P < 0.05). The weights of the testis and epididymis and the sperm concentration in the cauda of the epididymis of Group II were decreased significantly (P < 0.05) after acrylamide administration, while no significant change was observed in the sperm concentration of Group I (P > 0.05). Furthermore, histopathological lesions were presented in the testes of the treated rats, and the number of Leydig cells around the apoptosis seminiferous tubules increased significantly (P < 0.05).</p><p><b>CONCLUSION</b>Acrylamide has toxic effects on seminiferous tubules and decreases the production of sperm in male rats.</p>