Related Experiment Video
Updated: Jun 16, 2026
An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Hormone replacement therapy and messenger RNA expression of estrogen receptor coregulators after exercise in
Christina M Dieli-Conwright1, Tanya M Spektor, Judd C Rice
1Division of Biokinesiology and Physical Therapy, Clinical Exercise Research Center, University of Southern California, Los Angeles, CA 90033, USA.
Unlabelled:
The use of hormone replacement therapy (HRT) is a potential treatment to relieve symptoms of menopause in postmenopausal women; however, the effects on skeletal muscle are unclear. Specifically, it is unknown if HRT enhances estrogen receptor (ER) transcriptional activation in skeletal muscle at rest and after resistance exercise.
Purpose:
To evaluate changes in the messenger RNA (mRNA) expression of ER coregulators (steroid receptor coactivator-1 (SRC-1) and silencing mediator of retinoid and thyroid receptors (SMRT)) in postmenopausal women after a maximal eccentric exercise bout.
Methods:
Fourteen postmenopausal women were divided into two groups: control, women not using HRT (n = 6, 59.2 +/- 4.2 yr, 63.1 +/- 17.4 kg); or HRT, women using traditional HRT (n = 8, 58.5 +/- 3.7 yr, 89.5 +/- 23.7 kg). Participants performed 10 sets of 10 maximal eccentric repetitions of single-leg extension on the Cybex dynamometer at 60 degrees .s with 20-s rest periods between sets. Muscle biopsies of the vastus lateralis were obtained from the exercised leg at baseline and 4 h after the exercise bout. mRNA expression was determined using real-time polymerase chain reaction for SRC-1 and SMRT.
Results:
mRNA expression of SRC-1 significantly increased (P < or = 0.01; 2.4- to 5.2-fold change) and mRNA expression of SMRT significantly decreased (P < or = 0.01; -1.3- to -4.3-fold change) after the exercise bout in both groups. We observed significantly greater changes in mRNA expression of SRC-1 and SMRT (P < or = 0.01) in the HRT group compared with controls after exercise.
Conclusions:
A single bout of maximal eccentric exercise enhances ER transcriptional activity with a greater response present in postmenopausal women using HRT.
Related Concept Videos
01:22Hormonal 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.
01:30Hormonal 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...
01:33Hormonal Regulation
01:40Hormonal Regulation
01:26Secondary Messengers in Hormone Action
Many hormones bind to transmembrane G protein-coupled receptors that connect to regulatory G proteins. These G proteins can then activate enzymes such as adenylyl cyclase or phospholipase C. Adenylyl cyclase converts ATP to cAMP, activating...
01:24Gonadal 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...