Estrone
Encyclopedia
Estrone is an estrogen
ic hormone
secreted by the ovary
as well as adipose tissue
.
Estrone is one of several natural estrogen
s, which also include estriol
and estradiol
. Estrone is the least abundant of the three hormone
s; estradiol is present almost always in the reproductive female body, and estriol is abundant primarily during pregnancy
.
Estrone is relevant to health and disease states because of its conversion to estrone sulfate
, a long-lived derivative. Estrone sulfate acts as a reservoir that can be converted as needed to the more active estradiol.
Estrone is the predominant estrogen in postmenopausal women.
from androstenedione
, a derivative of progesterone
. The conversion consists of the de-methylation
of C-19 and the aromaticity of the 'A' ring. This reaction is similar to the conversion of testosterone
to estradiol.
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
ic hormone
Hormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...
secreted by the ovary
Ovary
The ovary is an ovum-producing reproductive organ, often found in pairs as part of the vertebrate female reproductive system. Ovaries in anatomically female individuals are analogous to testes in anatomically male individuals, in that they are both gonads and endocrine glands.-Human anatomy:Ovaries...
as well as adipose tissue
Adipose tissue
In histology, adipose tissue or body fat or fat depot or just fat is loose connective tissue composed of adipocytes. It is technically composed of roughly only 80% fat; fat in its solitary state exists in the liver and muscles. Adipose tissue is derived from lipoblasts...
.
Estrone is one of several natural estrogen
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
s, which also include estriol
Estriol
Estriol is one of the three main estrogens produced by the human body.-Synthesis:Estriol is only produced in significant amounts during pregnancy as it is made by the placenta from 16-Hydroxydehydroepiandrosterone sulfate , an androgen steroid made in the fetal liver and adrenal glands.The human...
and estradiol
Estradiol
Estradiol is a sex hormone. Estradiol is abbreviated E2 as it has 2 hydroxyl groups in its molecular structure. Estrone has 1 and estriol has 3 . Estradiol is about 10 times as potent as estrone and about 80 times as potent as estriol in its estrogenic effect...
. Estrone is the least abundant of the three hormone
Hormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...
s; estradiol is present almost always in the reproductive female body, and estriol is abundant primarily during pregnancy
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
.
Estrone is relevant to health and disease states because of its conversion to estrone sulfate
Estrone sulfate
Estrone sulfate is a sulfated estrone.It has been described as a prognosis indicator for prostate cancer.It is a component of Premarin....
, a long-lived derivative. Estrone sulfate acts as a reservoir that can be converted as needed to the more active estradiol.
Estrone is the predominant estrogen in postmenopausal women.
Biosynthesis
Estrone is synthesized via aromataseAromatase
Aromatase is an enzyme responsible for a key step in the biosynthesis of estrogens. It is a member of the cytochrome P450 superfamily , which are monooxygenases that catalyze many reactions involved in steroidogenesis. In particular, aromatase is responsible for the aromatization of androgens into...
from androstenedione
Androstenedione
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.-Synthesis:Androstenedione is the common precursor of male and female sex...
, a derivative of progesterone
Progesterone
Progesterone also known as P4 is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy and embryogenesis of humans and other species...
. The conversion consists of the de-methylation
Methylation
In the chemical sciences, methylation denotes the addition of a methyl group to a substrate or the substitution of an atom or group by a methyl group. Methylation is a form of alkylation with, to be specific, a methyl group, rather than a larger carbon chain, replacing a hydrogen atom...
of C-19 and the aromaticity of the 'A' ring. This reaction is similar to the conversion of testosterone
Testosterone
Testosterone is a steroid hormone from the androgen group and is found in mammals, reptiles, birds, and other vertebrates. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands...
to estradiol.