Estrogens (also oestrogens) are a group of steroid compounds, named for their importance in the oestrus cycle, functioning as the primary female sex hormone. While estrogens are present in both men and women, they are usually present at significantly higher levels in women of reproductive age. They promote the development of female secondary sex characteristics, such as breasts, and are also involved in the thickening of the endometrium and other aspects of regulating the menstrual cycle. Follicle stimulating hormone (FSH) and luteinizing hormone (LH) regulate the production of estrogen in ovulating women. Since estrogen circulating in the blood can feedback to reduce circulating levels of FSH and LH, some oral contraceptives contain estrogens.

The three major naturally occurring estrogens in women are estradiol, estriol and estrone. From menarche to menopause the primary estrogen is estradiol 17beta. In the body these are all produced from androgens through enzyme action. Estradiol is produced from testosterone and estrone from androstenedione. Estrone is weaker than estradiol, and in post-menopausal women more estrone is present than estradiol.

Estrogen production

---

Estrogen is produced primarily by developing follicles in the ovaries, the corpus luteum and the placenta. Some estrogens are also produced in smaller amounts by other tissues such as the liver, adrenal glands and the breasts. These secondary sources of estrogen are especially important in post-menopausal women. Synthesis of oestrogenes starts in theca interna cells in the ovary, by the synthesis of androstenedione from cholesterol. Androstenedione is a substance of moderate androgenic activity. This compound crosses the basal membrane into the surrounding granulosa cells, where it is converted to estrone or estradiol, either immediately or through testosterone. There is evidence that a testosterone supplement can support female sexual desire (Braunstein et al, 2005). Many studies of the role of sex steroid hormones on sexual desire have been done in naturally post-menopausal women or women who have had their ovaries surgically removed. Such studies have found better correlation between sexual desire and androgen levels than for estrogen levels (Warnock et al, 2005). A clinical study found that women aged 18 to 44 who reported low sexual desire tended to have low levels of dehydroepiandrosterone sulfate (Davis et al, 2005). Dehydroepiandrosterone is an abundant sex steroid in women and like other steroids is efficiently sulfated. Dehydroepiandrosterone (DHEA) is a precursor steroid that can be converted to estrogens (estradiol) and androgens such as testosterone and 5α-dihydrotestosterone. Estrogens can be produced by the enzyme aromatase which converts androgens such as DHEA to estrogens, mainly estradiol and estrone. Estriol is the third major human estrogen.

More on [ Estrogen ]

CFDA: FDA Latest Computer Systems Warning Letters

WL Issued to Amrex Zetron Inc
FDA Tue, 14 Apr 2009 00:00:00 -0400
FDA Warning Letter Issued to Amrex Zetron Inc on 14 Apr 2009 by Los Angeles District Office
WL Issued to Coast Institutional Review Board
FDA Tue, 14 Apr 2009 00:00:00 -0400
FDA Warning Letter Issued to Coast Institutional Review Board on 14 Apr 2009 by Center for Drug Evaluation and Research
WL Issued to Branitz, Bruce, MD
FDA Thu, 09 Apr 2009 00:00:00 -0400
FDA Warning Letter Issued to Branitz, Bruce, MD on 09 Apr 2009 by Center for Drug Evaluation and Research
WL Issued to Cote, Charles J., MD
FDA Mon, 02 Mar 2009 00:00:00 -0400
FDA Warning Letter Issued to Cote, Charles J., MD on 02 Mar 2009 by Center for Drug Evaluation and Research
WL Issued to Genzyme Corporation
FDA Fri, 27 Feb 2009 00:00:00 -0400
FDA Warning Letter Issued to Genzyme Corporation on 27 Feb 2009 by New England District Office
WL Issued to Hammill Manufacturing Company
FDA Tue, 06 Jan 2009 00:00:00 -0400
FDA Warning Letter Issued to Hammill Manufacturing Company on 06 Jan 2009 by Cincinnati District Office

CFDA: FDA Latest Drug GCP Warning Letters

WL Issued to Coast Institutional Review Board
FDA Tue, 14 Apr 2009 00:00:00 -0400
FDA Warning Letter Issued to Coast Institutional Review Board on 14 Apr 2009 by Center for Drug Evaluation and Research
WL Issued to Branitz, Bruce, MD
FDA Thu, 09 Apr 2009 00:00:00 -0400
FDA Warning Letter Issued to Branitz, Bruce, MD on 09 Apr 2009 by Center for Drug Evaluation and Research
WL Issued to Bukowski, Ronald M, MD
FDA Mon, 30 Mar 2009 00:00:00 -0400
FDA Warning Letter Issued to Bukowski, Ronald M, MD on 30 Mar 2009 by Center for Drug Evaluation and Research
WL Issued to Youabian, Inc
FDA Tue, 17 Mar 2009 00:00:00 -0400
FDA Warning Letter Issued to Youabian, Inc on 17 Mar 2009 by Los Angeles District Office
WL Issued to Provena St. Joseph's Medical Center IRB
FDA Thu, 12 Mar 2009 00:00:00 -0400
FDA Warning Letter Issued to Provena St. Joseph's Medical Center IRB on 12 Mar 2009 by Center for Biologics Evaluation and Research
WL Issued to Paulson, Daniel M., MD
FDA Wed, 11 Mar 2009 00:00:00 -0400
FDA Warning Letter Issued to Paulson, Daniel M., MD on 11 Mar 2009 by Center for Drug Evaluation and Research

Subscribe to Drugs_and_Medications RSS feed