Progesterone plays a central role in women's reproductive health. Synthetic progestins, such as medroxyprogesterone acetate (MPA) are often used in hormone replacement therapy (HRT), oral contraceptives, and for the treatment of endometriosis and infertility. Although MPA is clinically effective, it also promiscuously binds to androgen and glucocorticoid receptors (AR/GR) leading to many undesi...

The impact of progesterone on the cardiovascular system is relevant, but not as well characterized as the effects of estrogens. The recent early interruption of the conjugated equine estrogens (CEE)-medroxyprogesterone acetate (MPA) arm of the Women's Health Initiative trial, but not of the parallel CEE-only treatment arm, suggesting the possibility of harmful cardiovascular effects of the prog...

Many progestins have been developed for use in contraception, menopausal hormone therapy, and treatment of gynecological diseases. They are derived from either progesterone or testosterone, and they act by binding to the progesterone receptor (PR), a hormone-inducible transcription factor belonging to the nuclear receptor superfamily. Unlike mineralocorticoid, glucocorticoid, and androgen recep...

Abstract In 1960, the first hormonal contraceptive agent, Enovid approved by Food and Drug Administration in United States. The pill contained mestranol 150 mcg norethynodrel 10 mg. High dose pills containing >50 of estrogen were discontinued 1988 due to a higher risk myocardial infraction stroke secondary thrombosis. Until recently, only estrogens used combination OCPs ethinyl estradiol...

Estrous synchronization and artificial insemination have potential to increase the rate of genetic improvement, calf uniformity and improve calf weaning weight in beef cattle operations. Synchronization programs utilizing exogenous progestins, gonadotropin releasing hormone (GnRH), and prostaglandin (PGF 2 α) have been shown to be effective for estrous synchronization in beef cows and heifers (...

The use of combined hormone replacement therapy (HRT) with oestrogens and progestins in postmenopausal women has been associated with an increased risk for developing breast cancer. The reasons are not fully understood, but influence of HRT on endogenous conversion of female sex hormones may be involved. The expression of 17β hydroxysteroid dehydrogenases (17βHSD), which are enzymes catalysing ...

To determine the functional significance of the endogenous expression of the epidermal growth factor (EGF) and transforming growth factor-alpha genes in T-47D, human breast cancer cells, we have examined the effects of two types of antiproliferative agents, progestins and antiestrogens, on the expression of these growth factors and the effects of exogenous EGF on the antiproliferative action of...