antiandrogen

(redirected from Androgen antagonists)
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androgen

 [an´dro-jen]
any steroid hormone that promotes male secondary sex characters. The two main androgens are androsterone and testosterone. Called also androgenic hormone. adj., adj androgen´ic. 

The androgenic hormones are internal endocrine secretions circulating in the bloodstream and manufactured mainly by the testes under stimulation from the pituitary gland. To a lesser extent, androgens are produced by the adrenal glands in both sexes, as well as by the ovaries in women. Thus women normally have a small percentage of male hormones, in the same way that men's bodies contain some female sex hormones, the estrogens. Male secondary sex characters include growth of the beard and deepening of the voice at puberty. Androgens also stimulate the growth of muscle and bones throughout the body and thus account in part for the greater strength and size of men as compared to women.
androgen insensitivity syndrome complete androgen resistance.

an·ti·an·dro·gen

(an'tē-an'drō-jen),
Any substance capable of preventing full expression of the biologic effects of androgenic hormones on responsive tissues, either by producing antagonistic effects on the target tissue, as estrogens do, or by merely inhibiting androgenic effects, such as by competing for binding sites at the cell surface.

antiandrogen

(ăn′tē-ăn′drə-jən, ăn′tī-)
n.
A substance that inhibits the biological effects of androgenic hormones.

antiandrogen

Endocrinology A hormone or other agent–eg, megestrol acetate, spironolactone, flutamide, nilutamide, and cimetidine, which interferes with androgen function by competitively inhibiting androgen binding to cognate receptors at the target organ and is either biologically inert or functionally very weak; these compounds are used to manage androgen-dependent CAs–♂ breast and prostate, hirsutism, acne

Antiandrogen

A substance that blocks the action of androgens, the hormones responsible for male characteristics. Used to treat prostate cancers that require male hormones for growth.
Mentioned in: Prostate Cancer
References in periodicals archive ?
Low-level exposure to endocrine-disrupting compounds can induce functional, developmental, behavioral, and transgenerational disturbances, as shown after low-level exposure to the fungicide vin-clozolin, which acts as an androgen antagonist in rats and mice (Anway et al.
Selection for androgen receptor mutations in prostate cancers treated with androgen antagonist. Cancer Res 59(11):2511-2515.
Test substance VP SVCG LABC GP COWS Androgen agonists MT 8 8 8 8 8 TREN 3 3 3 3 3 Androgen antagonists PRO 5 5 5 4 5 VIN 8 8 8 7 8 LIN 3 4 4 1 3 DDE 9 9 9 9 9 5[alpha]-Reductase inhibitor FIN 4 4 4 3 4 Times a single tissue was 4 3 0 0 1 the most sensitive end point Times the tissue was equally 30 27 29 13 23 sensitive with at least one other tissue Times tissue was not 1 (a) 0 1 (a) 7 (a) 1 (a) statistically significant by either approach (a) One common instance was laboratory 6 with LIN.
Nine laboratories assessed the detection of the weak androgen antagonist DDE.
Four laboratories assessed the detection of this androgen antagonist using doses of 3, 10, 30, and 100 mg PRO/kg bw/day coadministered with 0.4 mg TP/kg bw/day.
Then, the assay was adapted for androgen antagonists such as flutamide (FLU) (Peets et al.
The protocols have been refined, and the next phases of the OECD validation program will test the protocol with selected doses of weak androgen agonists, androgen antagonists, a 5[alpha]-reductase inhibitor, and chemicals having no androgenic activity.
The objectives of the first phase of the OECD validation of the Hershberger bioassay were to a) demonstrate the reproducibility and sensitivity of the responses of five male sex accessory tissues to the action of a reference androgen, TP, hereafter phase 1A; b) assess the utility, reproducibility, and sensitivity of various other measured end points within and among participating laboratories in response to the action of TP; c) study the interaction of reference TP doses with a reference androgen antagonist, FLU, on the sex accessory tissues and other end points, hereafter phase 1B; and d) select standard reference doses of TP and FLU for future studies with weakly potent agonists, antagonists, and nonandrogenic test substances.
For the androgen antagonists (VCZ and p,p'-DDE), 0.2 mg/kg/day of TP was coadministered each day by subcutaneous injection in the dorsal region after the oral administration of each chemical.
This finding demonstrates that no significant differences exist regarding the use of SD and Wistar rats in the Hershberger assay for the detection of androgen antagonists.