16α-LE2, or 16α-lactone-estradiol, also known as 3,17β-dihydroxy-19-nor-17α-pregna-1,3,5-(10)-triene-21,16α-lactone, is a

synthetic Synthetic may refer to: Science * Synthetic biology * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic elements, chemical elements that are not naturally found on Earth and therefore have to be created in ...

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

estrogen Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...

featuring an

estradiol Estradiol (E2), also called oestrogen, oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of female reproductive cycles such as estrous and menstrual cycles. Estradiol is responsible ...

core. It is a highly potent and selective

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

of the

ERα Estrogen receptor alpha (ERα), also known as NR3A1 (nuclear receptor subfamily 3, group A, member 1), is one of two main types of estrogen receptor, a nuclear receptor (mainly found as a chromatin-binding protein) that is activated by the se ...

that is used in

scientific research The scientific method is an empirical method for acquiring knowledge that has been referred to while doing science since at least the 17th century. Historically, it was developed through the centuries from the ancient and medieval world. The ...

to study the function of the ERα. It has 265-fold higher

potency Potency may refer to: * Potency (pharmacology), a measure of the activity of a drug in a biological system * Virility * Cell potency, a measure of the differentiation potential of stem cells * In homeopathic dilutions, potency is a measure of ho ...

transactivation In the context of gene regulation: transactivation is the increased rate of gene expression triggered either by biological processes or by artificial means, through the expression of an intermediate transactivator protein. In the context of recep ...

assay An assay is an investigative (analytic) procedure in laboratory medicine, mining, pharmacology, environmental biology and molecular biology for qualitatively assessing or quantitatively measuring the presence, amount, or functional activity ...

s of the ERα relative to the

ERβ Estrogen receptor beta (ERβ) also known as NR3A2 (nuclear receptor subfamily 3, group A, member 2) is one of two main types of estrogen receptor—a nuclear receptor which is activated by the sex hormone estrogen. In humans ERβ is encoded by t ...

and 70-fold preference in

binding affinity In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. The etymology stems from Latin ''ligare'', which means 'to bind'. In protein-ligand binding, the ligand is usuall ...

for the ERα over the ERβ. In rodents, 16α-LE2 has no effect on

ovarian follicle An ovarian follicle is a roughly spheroid cellular aggregation set found in the ovaries. It secretes hormones that influence stages of the menstrual cycle. In humans, women have approximately 200,000 to 300,000 follicles at the time of puberty, ea ...

development, whereas the highly ERβ-selective agonist

8β-VE2 8β-VE2, or 8β-vinylestradiol, also known as 8β-vinylestra-1,3,5(10)-triene-3β,17β-diol, is a synthetic compound, synthetic estrogen (medication), estrogen featuring an estradiol (medication), estradiol core. It is a highly potency (pharmacol ...

stimulates follicular growth and to a comparable extent as

, indicating that the ERβ and not the ERα is involved in the effects of estrogen on ovarian follicles. In contrast, 16α-LE2 stimulates

uterine The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic and fetal development of one or more fertilized eggs until bir ...

weight, whereas 8β-VE2 has no effect, indicating that the ERα and not the ERβ is involved in the effects of estrogen on the uterus. Research has determined through experimental

rodent studies Rodents have been employed in biomedical experimentation from the 1650s. Rodent studies up to the early 19th century were mainly physiological or toxicological. The first rodent behavioral study was carried out in 1822, a purely observational st ...

with estradiol, 16α-LE2, and 8β-VE2 that the positive, protective effects of estrogens on

bone formation Ossification (also called osteogenesis or bone mineralization) in bone remodeling is the process of laying down new bone material by cells named osteoblasts. It is synonymous with bone tissue formation. There are two processes resulting in th ...

resorption Resorption is the absorption of cells or tissue into the circulatory system, usually by osteoclasts. Types of resorption include: * Bone resorption Bone resorption is resorption of bone tissue, that is, the process by which osteoclasts break ...

and

bone mineral density Bone density, or bone mineral density, is the amount of bone mineral in bone tissue. The concept is of mass of mineral per volume of bone (relating to density in the physics sense), although clinically it is measured by proxy according to opti ...

are mediated via the ERα, whereas the ERβ does not appear to be involved.

References

Estranes Lactones Synthetic estrogens Diols Hydroxyarenes Tertiary alcohols {{genito-urinary-drug-stub

See also

References