Related Experiment Video
Updated: Sep 27, 2026

An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Hormone therapy in menopause: the plot thickens
1Division of Medical Gynecology, Department of Obstetrics and Gynecology, Mayo Clinic Rochester, USA.
Abstract:
The termination of one of the trials in the Women's Health Initiative (WHI) study is causing turmoil in women using hormone therapy. Practitioners and patients alike are confronted with conflicting evidence about the safety and effectiveness of both estrogen therapy (ET) and hormone (estrogen/progestin) therapy (HT). Recent investigations of the estrogen receptor, the genome, and cellular cofactors have demonstrated the heterogeneity of molecular response to hormones. This implies a heterogeneous response in the individual as well and casts doubt on the validity of prior research. Recent experiments in monkeys have provided a possible explanation for the adverse effects of HT on the cardiovascular system that were detailed by the Heart and Estrogen/Progestin Replacement Study (HERS) and WHI studies. This article explores nuances of several key studies and discusses potential therapeutic options, including use of lower-dose estrogen, transdermal estrogen, selective estrogen-receptor modulators, and diminished use of progestin.
Related Concept Videos
Menopause
Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
Hormonal Regulation
Hormonal Regulation
Hormonal Control of the Ovarian Cycle
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
Gonadal and Placental Hormones
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair growth — and...