Hickson R C, Galassi T M, Capaccio J A, Chatterton R T
J Steroid Biochem. 1986 Jun;24(6):1179-83. doi: 10.1016/0022-4731(86)90380-8.
Male hypophysectomized rats were initially assigned to a control or an overloaded group that underwent compensatory hypertrophy of plantaris muscles to steady-state levels following removal of synergistic musculature. Plantaris muscle mass of overloaded animals was higher than that of controls by 38% (391 +/- 8 vs 284 +/- 7 mg) and glucocorticoid cytosol specific binding concentrations, using [3H]triamcinolone acetonide (TA) as the labeled steroid, was also significantly higher in hypertrophied muscles (83.3 +/- 3.9 fmol . mg protein-1) than in control muscles 56.3 +/- 3.9 fmol . mg protein-1). Cortisone acetate (CA) was then administered daily subcutaneously in high, 100 mg; intermediate, 10 mg; or low, 1.0 mg . kg-1 body wt doses. Groups of rats were killed after 1/4, 2 days and 7 days. Absolute muscle mass losses after 7 days of CA treatment were approx 80 mg with high doses and 60 mg with intermediate doses in both hypertrophied and control muscles. The low CA dose did not produce atrophy. The absolute depletion of [3H]TA binding activity with CA treatment was always greater in hypertrophied muscles of high and intermediate dose treated than those of their respective controls, but TA binding capacities remained higher in hypertrophied muscles than in controls at almost all time points in all treatment groups. Unlike previous findings in which the simultaneous initiation of overload prevented glucocorticoid induced muscle wasting, no resistance to the effect of CA treatment was observed when treatment was begun after hypertrophy had occurred.
雄性垂体切除大鼠最初被分为对照组或超负荷组，后者在去除协同肌肉组织后，其跖肌经历代偿性肥大直至达到稳态水平。超负荷组动物的跖肌质量比对照组高38%（分别为391±8mg和284±7mg），以[3H]曲安奈德（TA）作为标记类固醇，肥大肌肉中的糖皮质激素胞质溶胶特异性结合浓度（83.3±3.9fmol·mg蛋白-1）也显著高于对照肌肉（56.3±3.9fmol·mg蛋白-1）。然后，每天皮下注射醋酸可的松（CA），高剂量为100mg，中剂量为10mg，低剂量为1.0mg·kg-1体重。在1/4天、2天和7天后处死大鼠组。CA治疗7天后，肥大肌肉和对照肌肉的绝对肌肉质量损失，高剂量组约为80mg，中剂量组约为60mg。低剂量CA未产生萎缩。CA治疗后，高剂量和中剂量组肥大肌肉中[3H]TA结合活性的绝对消耗总是大于各自对照组，但在所有治疗组的几乎所有时间点，肥大肌肉中的TA结合能力仍高于对照组。与之前同时开始超负荷可预防糖皮质激素诱导的肌肉萎缩的研究结果不同，在肥大发生后开始治疗时，未观察到对CA治疗效果的抵抗。
