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Regulation of Reproduction by Dopamine
Published in Nira Ben-Jonathan, Dopamine, 2020
Ovarian steroids are critical for normal uterine function, for the establishment and maintenance of pregnancy, mammary gland development, and for the support of the female secondary sex characteristics. In most mammals (including humans) ovarian steroidogenesis occurs by a two-hormone/two-cell mechanism. Under this paradigm, the two gonadotropins, LH and FSH, and two cell types, theca and granulosa, work coordinately to produce the ovarian steroids. Theca cells, which are derived from the ovarian stroma, differentiate into endocrine cells under the influence of the growing dominant follicle (Figure 10.12A). The main steroidal product of the follicle is estrogen, while progesterone is the main product of the corpus luteum.
Herbal Management for Polycystic Ovarian Syndrome
Published in Megh R. Goyal, Hafiz Ansar Rasul Suleria, Ademola Olabode Ayeleso, T. Jesse Joel, Sujogya Kumar Panda, The Therapeutic Properties of Medicinal Plants, 2019
Huma Bader-Ul Ain, Farhan Saeed, Muhammad Umair Arshad, Hafiz Ansar Rasul Suleria
According to Dunne and Slater [39], motivators of PCOS are many hormones such as testosterone-producing androgen, cortisol, estrogens (female hormone), FSH, insulin (carrier of blood glucose to other cells), LH, progesterone (female hormone), prolactin, and thyroid hormones disturbances. In retort to prompt by LH, the ovarian theca-cells amalgamate androgens. It is revealed from in-vitro and in-vivo studies that chances of conversion of androgenic signs into testosterone are higher in case of PCOS women with abnormal theca cells in their ovaries as compared to normal women with normal theca cells [114].
Reproductive System and Mammary Gland
Published in Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard, Toxicologic Pathology, 2018
Justin D. Vidal, Charles E. Wood, Karyn Colman, Katharine M. Whitney, Dianne M. Creasy
In those follicles that continue to grow, granulosa cell proliferation continues and clefts begin to form in the zona granulosa; these spaces eventually coalesce, producing a single, fluid-filled antrum that characterizes the tertiary follicle. The antrum is lined by multiple layers of granulosa cells and the oocyte, which has now reached its maximum size, is encircled by granulosa cells (the cumulus oophorus) that form a stalk extending into the antral cavity. The layer of cumulus cells immediately adjacent to the zona pellucida, the corona radiata, will remain with the oocyte after ovulation. The theca interna cells of the tertiary follicle may be enlarged, ovoid to polygonal in shape and more prominent with vacuolated cytoplasm. Only a single follicle (in the NHP) or small number of follicles (in the rodent and dog) are at the appropriate developmental stage to respond to rapidly rising levels of FSH and it is these follicles that are recruited to continue to develop into pre-ovulatory (Graafian) follicle(s) (Fortune 1994).
CircEpha5 regulates the synthesis and secretion of androgen in mouse preantral follicles by targeting miR-758-5p
Published in Journal of Obstetrics and Gynaecology, 2023
Xueying Zhang, Jiaxuan Liu, Hao Wu, Yan Chen, Xuesen Zhang, Boqun Xu
It has been reported that most PCOS patients with hyperandrogenism exhibit steroid secretion defects, which can lead to abnormal folliculogenesis and a failure in dominant follicle selection (Zeng et al.2020). For example, overexpression of steroidogenesis acute regulator (StAR) in PCOS exhibited a state of hyperandrogenism (Kalyani et al.2018). The elevation of luteinizing hormone receptor (LHR) promotes the conversion of cholesterol into testosterone and androsterone, thus stimulating ovarian theca cells to produce excessive androgen (Ritu et al.2019). Studies have shown that CAG repeat polymorphisms in androgen receptor (AR) gene may cause hyperandrogenemia in PCOS (Ryan et al.2018). Theca cells from polycystic ovaries of classic PCOS patients overexpress most steroidogenic enzymes. Cytochrome P450 cholesterol side chain lyase (P450c11, encoded by CYP11A1 gene), catalyses the conversion of cholesterol to progesterenolone during steroid hormone synthesis. Cytochrome P450 17 A-hydroxylase and 17 and 20 carbon chain lyase (P450c17, CYP17A1 gene code) are rate-limiting enzymes for androgen production in the ovary and adrenal cortex (Belani et al.2018). The expression of enzymes related to androgen biosynthesis increases in follicular membrane cells of PCOS mice, and the level of testosterone also rises in the culture medium of PCOS follicular membrane cells (Jakimiuk et al.2001, Madeleine et al.2018). Studying the synthesis and secretion of androgen in follicles may provide new insight into the pathogenesis of PCOS hyperandrogenemia.
Medical journey of patients with polycystic ovary syndrome and obesity: a cross-sectional survey of patients and primary care physicians
Published in Postgraduate Medicine, 2023
Katherine Sherif, Jamie Coborn, Anthony Hoovler, Lisa Gill
Insulin resistance leads to compensatory hyperinsulinemia which causes neuroendocrine disruptions in the hypothalamic-pituitary-ovarian axis. It is thought that compensatory hyperinsulinemia and enhanced pituitary sensitivity to gonadotropin releasing hormone (GnRH) leads to overproduction of luteinizing hormone (LH) [18]. Increased LH expression coupled with normal or low follicle stimulating hormone expression leads to overproduction of androgens in the theca cells of the ovaries [19]. The increased production of androgens can, in turn, increase insulin resistance by interfering with insulin signaling and by triggering lipolysis [18]. Therefore, insulin resistance and hyperandrogenemia can act as a complicated positive feedback loop that worsens PCOS and obesity. These metabolic pathways can be influenced by genetic and environmental factors that are highly heterogenous across patients with PCOS and obesity and are areas of active research [18].
The reproductive endocrine feature and conception outcome of women with unknown etiological menstrual cycle (36–45 days) with long follicular phase
Published in Gynecological Endocrinology, 2022
Zhewei Wang, Jiongjiong Yan, Huifen Chen, Laman He, Shaohua Xu
The hypothalamic–pituitary–ovarian axis (HPOA) mainly affects the development of follicles. Adversely, the abnormality in the amount or the cyclicity of sexual hormones secreted by the ovary is either not enough to stimulate follicular stimulating hormone (FSH) secretion, or cannot reach the peak of luteinizing hormone (LH) secretion during ovulation leading to the slow development of follicles and ovulation disorder. Ovarian local regulatory factors INH (inhibin), ACT (activin), and FS (follistatin) also play crucial roles in follicle recruitment and the selection of dominant follicles. INH regulates follicle-stimulating synthesis and release of FSH and stimulates the biosynthesis of androgen by theca cells. ACT enhances the expression of the FSH receptor, improves FSH secretion, and inhibits effect of LH on androgen secretion. FS is a binding protein of ACT and INH, which inhibits the aromatase activity of granulosa cells and resists effect of ACT on follicles. The abnormality of INH–ACT–FS system leads to the failure of oocyte maturation. INH is a heterodimer glycoprotein hormone formed by the disulfide bond between an α subunit and one kind of ß subunits (ßA, ßB) and INHB (α-ßB)is mainly in pre-ovulatory follicles. ACT consists of two kinds of ß subunits and the main active form is ACTA (ßAßA). Therefore, we evaluated the ratio of FSH/LH and INHB, ACTA, and FS.