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Estrogens (also oestrogens) are a group of steroid compounds that function as the primary female sex hormone. A steroid is a lipid characterized by a carbon skeleton with four fused rings. ...
A hormone (from Greek horman - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ...
The three naturally occurring estrogens are estradiol, estriol and estrone. 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. Estradiol (17-beta estradiol) is a sex hormone. ...
Estriol is one of the three main estrogens produced by the human body. ...
Structural formula of estrone Estrone is an estrogenic hormone secreted by the ovary. ...
Androgen is the generic term for any natural or synthetic compound, usually a steroid hormone, that stimulates or controls the development and maintenance of masculine characteristics in vertebrates by binding to androgen receptors. ...
Testosterone is a steroid hormone from the androgen group. ...
Jump to: navigation, search Androstenedione is a 19-carbon steroid hormone produced in the adrenal glands and the gonads as an intermediate step in the biochemical pathway that produces the androgen testosterone and the estrogens estrone and estradiol. ...
Chemistry
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. Presence of both cell types is essential for estrogen synthesis. Human female internal reproductive anatomy Ovaries are a part of a female organism that produces eggs. ...
Jump to: navigation, search Androstenedione is a 19-carbon steroid hormone produced in the adrenal glands and the gonads as an intermediate step in the biochemical pathway that produces the androgen testosterone and the estrogens estrone and estradiol. ...
Cholesterol is a steroid, a lipid, and an alcohol, found in the cell membranes of all body tissues, and transported in the blood plasma of all animals. ...
Cells in culture, stained for keratin The cell is the structural and functional unit of all living organisms. ...
Testosterone is a steroid hormone from the androgen group. ...
Sources Estrogens are 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 liver, adrenal glands and the breasts. These secondary sources of estrogen are especially important in post-menopausal women. Human female internal reproductive anatomy Ovaries are a part of a female organism that produces eggs. ...
The corpus luteum (Latin for yellow body) is a small, temporary endocrine structure in mammals that develops from an ovarian follicle during the luteal phase of the menstrual cycle, following the release of a mature egg during ovulation. ...
Human placenta shown a few minutes after birth. ...
Jump to: navigation, search The liver is an organ in vertebrates, including humans. ...
In mammals, the adrenal glands (also known as suprarenal glands or colloquially as kidney hats) are the triangle-shaped endocrine glands that sit atop the kidneys. ...
Jump to: navigation, search Human female breasts The term breast, also known by the Latin mamma in anatomy, refers to the upper ventral region of an animals torso, particularly that of mammals, including human beings. ...
Menopause (also known as the Change of life or climacteric) is a stage of the human female reproductive cycle that occurs as the ovaries stop producing estrogen, causing the reproductive system to gradually shut down. ...
Effects While estrogens are present in both men and women, they are found in women in significantly higher quantities. They promote the development of female secondary sexual characteristics, such as breasts, and are also involved in the thickening of the endometrium and other aspects of regulating the menstrual cycle, which is why many oral contraceptives contain estrogens. Secondary sex characteristics are traits that distinguish the two sexes of a species, but that are not directly part of the reproductive system. ...
The endometrium is the uterine membrane in mammals which is thickened in preparation for the implantation, of a fertilized egg upon its arrival into the uterus. ...
Jump to: navigation, search Menstrual cycle The menstrual cycle is the set of recurring physiological changes in a females body that are under the control of the reproductive hormone system and necessary for reproduction. ...
Jump to: navigation, search Oral contraceptives are chemicals taken by mouth to inhibit normal fertility. ...
Medical applications The use of estrogen, especially together with a progestin, is a treatment for the symptoms of menopause which is controversially alleged to do as much harm as good because of the Women's Health Initiative and related studies, which have been sensationally reported. Many professional bodies have suggested that the problems may be due only to the particular product(s) (Premarin alone and with Provera as Prempro) and fixed doses used in all the recent studies[1] and extensive research is underway to absolutely confirm the precise processes of such variations. A progestin is a synthetic progestagen. ...
Menopause (also known as the Change of life or climacteric) is a stage of the human female reproductive cycle that occurs as the ovaries stop producing estrogen, causing the reproductive system to gradually shut down. ...
The Womens Health Initiative (WHI) was initiated by the National Institutes of Health (NIH) in 1991. ...
Premarin is a mixture of estrogens isolated from horse urine (PREgnant MARes urINE). ...
Estrogen and lung disease Among people over 70 who have never smoked, women make up 85 percent of those with chronic obstructive pulmonary disease (COPD). Studies with mice (see below) suggest the possibility that COPD incidence may be tied to decreases in estrogen as women age. Chronic obstructive pulmonary disease (COPD) is an umbrella term for a group of respiratory tract diseases that are characterised by airflow obstruction or limitation. ...
Female mice that had their ovaries removed to deprive them of estrogen lost 45 percent of their working alveoli from their lungs. Upon receiving estrogen, the mice recovered full lung function. The alveoli (singular:alveolus), tiny hollow sacs which are continuous with the airways, are the sites of gas exchange with the blood. ...
Two proteins that are activated by estrogen play distinct roles in breathing. One protein builds new alveoli, the other stimulates the alveoli to expel carbon dioxide. Loss of estrogen hampered both functions in the test mice. (Massaro & Massaro, 2004) A representation of the 3D structure of myoglobin, showing coloured alpha helices. ...
Jump to: navigation, search Carbon dioxide is an atmospheric gas composed of one carbon and two oxygen atoms. ...
Estrogenic compounds A range of other synthetic and natural substances have been identified that possess estrogenic activity. These include bisphenol-A, phthalate esters and nonylphenol. Chemical structure of Bisphenol A Bisphenol A is a chemical compound that is prepared by reaction of two equivalents of phenol with one equivalent of acetone. ...
Jump to: navigation, search Nonylphenol is an organic compound of the wider family of alkylphenols. ...
References - Massaro D, Massaro GD (2004). Estrogen regulates pulmonary alveolar formation, loss, and regeneration in mice. American Journal of Physiology. Lung Cellular and Molecular Physiology 287 (6): L1154-9. PMID 15298854
External links The United States National Library of Medicine (NLM), operated by the United States federal government, is the worlds largest medical library. ...
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