Dahlberg E, Snochowski M, Gustafsson J A
Endocrinology. 1981 Apr;108(4):1431-40. doi: 10.1210/endo-108-4-1431.
Using a charcoal technique, we determined the relative binding affinity of some anabolic compounds for the androgen and glucocorticoid receptors in cytosol from rat skeletal muscle. Only a few of the compounds analyzed competed for the receptor-binding sites. The androgen and glucocorticoid receptors were analyzed in rat and mouse skeletal muscle cytosols by Scatchard analysis. In rats grouped according to sex and age, the cytosolic protein content was about the same in all groups, but the DNA content decreased with increased weight of the animal regardless of sex (male, female, or castrated male). The glucocorticoid receptor did not differ in concentration (2-3 pmol/g tissue) or ligand affinity (Kd, 10-40 nM) among the groups, but the androgen receptor concentration decreased with increased weight and age of the animals, more in the case of males than in the case of females or castrates. The Kd for the androgen receptor increased with age in males but was constantly about 0.2 nM for castrates or females. In adult intact rats, the androgen and glucocorticoid receptor concentrations in muscle cytosol from females were about 100 and 3000 fmol/g tissue, respectively, the corresponding values for males being about 50 and 2000 fmol/g tissue, respectively. Short term castration or adrenalectomy increased the concentration of and ligand affinity for the androgen and glucocorticoid receptors, respectively. After long term castration of male rats, the concentration of both receptors increased during 5 weeks to about the female level, only to decrease later. Neonatally castrated male rats had about the same androgen receptor concentrations and Kd values as female rats. Female mice had higher androgen receptor concentrations (approximately 700 fmol/g tissue) than rats. Intact male mice had about 200 fmol androgen receptor-binding sites/g tissue, and the same amount was found in mice bearing the testicular feminization (Tfm) mutant gene. In summary, the concentrations of androgen and glucocorticoid receptors in rat skeletal muscle are regulated at least by the testes. The presence of androgen receptors in skeletal muscle from Tfm mice is surprising and may motivate a reinvestigation of the regulation of androgen receptors in Tfm animals.
我们采用活性炭技术，测定了一些合成代谢化合物对大鼠骨骼肌胞质溶胶中雄激素受体和糖皮质激素受体的相对结合亲和力。在所分析的化合物中，只有少数几种能竞争受体结合位点。通过Scatchard分析对大鼠和小鼠骨骼肌胞质溶胶中的雄激素受体和糖皮质激素受体进行了分析。在按性别和年龄分组的大鼠中，所有组的胞质蛋白含量大致相同，但无论性别（雄性、雌性或去势雄性），DNA含量均随动物体重增加而降低。各组间糖皮质激素受体的浓度（2 - 3 pmol/g组织）或配体亲和力（Kd，10 - 40 nM）并无差异，但雄激素受体浓度随动物体重和年龄增加而降低，雄性大鼠的降低幅度大于雌性大鼠或去势大鼠。雄性大鼠雄激素受体的Kd随年龄增加，而去势大鼠或雌性大鼠的Kd始终约为0.2 nM。在成年未阉割大鼠中，雌性肌肉胞质溶胶中雄激素受体和糖皮质激素受体的浓度分别约为100和3000 fmol/g组织，雄性的相应值分别约为50和2000 fmol/g组织。短期去势或肾上腺切除分别增加了雄激素受体和糖皮质激素受体的浓度及配体亲和力。雄性大鼠长期去势后，两种受体的浓度在5周内增加至约雌性水平，随后又降低。新生期去势的雄性大鼠雄激素受体浓度和Kd值与雌性大鼠大致相同。雌性小鼠的雄激素受体浓度（约700 fmol/g组织）高于大鼠。完整雄性小鼠每克组织约有200 fmol雄激素受体结合位点，携带睾丸雌性化（Tfm）突变基因的小鼠中也发现了相同的量。总之，大鼠骨骼肌中雄激素受体和糖皮质激素受体的浓度至少受睾丸调节。Tfm小鼠骨骼肌中存在雄激素受体令人惊讶，可能促使重新研究Tfm动物中雄激素受体的调节。
