Kasper C E
School of Nursing, University of California, Los Angeles 90095-6918, USA.
J Appl Physiol (1985). 1995 Aug;79(2):607-14. doi: 10.1152/jappl.1995.79.2.607.
The purpose of this study was to determine whether reloading of atrophied skeletal muscle after 28 days of hind-limb unloading (HU) would produce significant sarcolemmal membrane disruption before frank necrosis. Soleus and plantaris muscles were atrophied by HU. Adult female Wistar rats (N = 13) were killed at 28 days of unloading and 4 and 7 days of reloading after HU. Rat serum albumin was used as a marker for muscle fiber disruption. Dark intracellular staining with horseradish peroxidase-conjugated anti-rat serum albumin antibody was interpreted as evidence of membrane rupture. There was a significantly different time course of disruption between plantaris and soleus muscles, with a negative correlation between cell size and occurrence of disruption. Fourteen percent of plantaris fibers were wounded after HU, peaking at day 4 of reloading (20% of cross-sectional area). Soleus demonstrated disruption only on reloading peaking in severity at day 7 (14% of fibers). It was demonstrated that sarcolemmal disruption due to atrophy and reloading does not always progress to necrosis and degeneration by the 7th day of recovery.
本研究的目的是确定后肢卸载（HU）28天后萎缩骨骼肌重新加载是否会在明显坏死之前导致肌膜显著破坏。比目鱼肌和跖肌因HU而萎缩。成年雌性Wistar大鼠（N = 13）在卸载28天以及HU后重新加载4天和7天时处死。大鼠血清白蛋白用作肌纤维破坏的标志物。用辣根过氧化物酶偶联的抗大鼠血清白蛋白抗体进行的深色细胞内染色被视为膜破裂的证据。跖肌和比目鱼肌之间的破坏时间进程存在显著差异，细胞大小与破坏发生率呈负相关。HU后14%的跖肌纤维受损，在重新加载第4天达到峰值（横截面积的20%）。比目鱼肌仅在重新加载时出现破坏，在第7天严重程度达到峰值（14%的纤维）。结果表明，由于萎缩和重新加载导致的肌膜破坏在恢复第7天时并不总是会发展为坏死和退化。
