Saartok T
Int J Sports Med. 1984 Jun;5(3):130-6. doi: 10.1055/s-2008-1025894.
Radiolabeled synthetic steroid hormones and a charcoal adsorption assay were used to identify cytosolic androgen, glucocorticoid, and estrogen receptors in skeletal muscle from rabbits. The presence of the receptors was verified by saturation analysis showing low-capacity, high-affinity binding for the steroid-receptor complexes, specific for each class of steroids. The concentration of androgen and estrogen receptors were of the same magnitude, whereas the corresponding value for the glucocorticoid receptor was about tenfold higher. Comparisons of fast-twitch (the gastrocnemius/plantaris complex) and slow-twitch (soleus) muscles revealed that the latter contained higher concentrations (expressed per g of tissue wet weight) of glucocorticoid and estrogen receptors, but not of androgen receptor. Expressed per mg of soluble protein, the slow-twitch muscle contained higher concentrations of all three receptors, but when related to the concentrations of all three receptors, but when related to the concentration of DNA, only the concentration of estrogen receptor was higher in the slow-twitch muscle. Different response of the two fiber types to direct action of steroid hormones can hence be expected. The fast-twitch muscle contained a higher concentration of soluble protein, whereas the slow-twitch muscle contained higher concentration of DNA, resulting in lower protein/DNA ratio, i.e., smaller "cell units," in the latter muscle.
利用放射性标记的合成甾体激素和活性炭吸附试验，鉴定了兔骨骼肌中的胞质雄激素、糖皮质激素和雌激素受体。通过饱和分析证实了受体的存在，该分析显示甾体-受体复合物具有低容量、高亲和力结合，且对每类甾体具有特异性。雄激素和雌激素受体的浓度处于同一水平，而糖皮质激素受体的相应值约高10倍。对快肌（腓肠肌/跖肌复合体）和慢肌（比目鱼肌）的比较显示，慢肌中糖皮质激素和雌激素受体的浓度（以每克组织湿重表示）更高，但雄激素受体并非如此。以每毫克可溶性蛋白表示，慢肌中三种受体的浓度均更高，但当与三种受体的浓度相关时，若与DNA浓度相关，只有慢肌中雌激素受体的浓度更高。因此，可以预期两种纤维类型对甾体激素直接作用的反应不同。快肌中可溶性蛋白的浓度较高，而慢肌中DNA的浓度较高，导致后者的蛋白/DNA比值较低，即“细胞单位”较小。
