Estrogen Receptor in Bovine Skeletal Muscle

Abstract

In connection with investigations of the anabolic action of estrogens, we examined skeletal muscle of veal calves for estradiol receptors. The high speed supernatant of muscle homogenate was incubated with .5 nM 3H-estradiol and for the determination of nonspecific binding with .5 nM 3H-estradiol plus 13 nM estradiol at 0 C overnight. After treatment with charcoal two times, the supernatant was analyzed by agar gel electrophoresis. Specific binding was found in the typical position of cytosolic estradiol receptor. Ninety percent of 3H-estradiol binding was suppressed by estradiol-17 beta, zeranol, estrone or diethylstilbestrol, but was not affected by testosterone, dihydrotestosterone, trenbolone or progesterone. The specific binding activity varied between .3 and 2.0 fmol/mg protein and the dissociation constant of the receptor was Kd = 60 pM. After an enrichment up to 42 fmol/mg cytosolic protein using heparin sepharose, the receptor remained unchanged as determined by agar gel electrophoresis. Although uterine tissue generally contains 1,000 times more estradiol receptors, these results clearly demonstrate that skeletal muscle also contains estradiol receptors with identical properties. This indicates that one possible component of the anabolic action of estrogens may be the direct stimulation of the muscle via the estradiol receptor.

Effects of chlortetracycline and Synovex-S® on growth rate and on plasma growth hormone and thyroid hormone concentrations following administration of thyrotropin-releasing hormone and GH-releasing hormone in beef steers

“…Our data also support the notion that the releasable GH pool may have been greater for the implanted animals, and the pool of TSH and T 3 was greater for steers receiving Synovex-S. It is important to note that estrogenic implants may have a direct effect on skeletal muscle protein synthesis due to the presence of high-affinity, estrogen receptors, which have been identified in bovine skeletal muscle (Meyer and Rapp 1985;Sauerwein and Meyer 1989). The most likely mode of action for the increased protein accretion observed with the administration of estrogenic implants is a combination of increased GH and thyroid hormone secretion rates, as well as some direct effects of the estrogen on skeletal muscle cells.…”

Changes in maximal voluntary force of human adductor pollicis muscle during the menstrual cycle.

“…Therefore, we conclude that oestrogen does have a strengthening action, directly or indirectly, on skeletal muscle. We suggest that this effect, because of its probable delayed onset, is likely to be mediated by the classical steroid receptor for oestrogen which has been described in animal (Dahlberg, 1982;Saartok, 1984;Meyer & Rapp, 1985) and human muscle (Smith, Heimer, Norgren & Ulmsten, 1990), rather than the membrane receptor postulated by Sarwar et al (1995), which would be expected to show a more rapid onset of action.…”

The effect of hormone replacement therapy and/or exercise on skeletal muscle attenuation in postmenopausal women: a yearlong intervention

“…In addition, the exercise compliance requirements were low as the primary focus of this study was the hormonal effects on the musculoskeletal system. It has long been known that skeletal muscle from various animals contain ER (Dionne et al, 1979;Saartok, 1984;Meyer & Rapp, 1985), and Lemoine et al (2003) recently demonstrated the presence of ER alpha in human deltoid and pectoral skeletal muscles. Similarly, Sipilä & Suominen (1995) have shown an improvement in HU of leg muscles in older women following 18 weeks of strength training, and Bergman et al (1999) reported a decrease in resting quadriceps triglyceride concentrations in young men following cycle ergometer training which would result in an increase in muscle density (Goodpaster et al, 2000(Goodpaster et al, , 2001.…”