Oishi Y, Ishihara A, Talmadge R J, Ohira Y, Taniguchi K, Matsumoto H, Roy R R, Edgerton V R
Laboratory of Muscle Physiology, Faculty of Education, Kumamoto University, Japan.
Acta Physiol Scand. 2001 Jun;172(2):123-30. doi: 10.1046/j.1365-201X.2001.00847.x.
Changes in the expression of heat shock protein 72 (HSP72) in response to atrophic-inducing perturbations of muscle involving chronic mechanical unloading and denervation were determined. Adult male Wistar rats were assigned randomly to a sedentary cage control (CON), hind limb unloading (HU, via tail suspension), HU plus tenotomy (HU + TEN), HU plus denervation (HU + DEN), or HU + TEN + DEN group. Tenotomy and DEN involved cutting the Achilles tendon and removing a segment of the sciatic nerve, respectively. After 5 days, HSP72 levels in the soleus of the HU + DEN and HU + TEN + DEN groups were 42 (P < 0.05) and 53% (P < 0.01) less than CON, respectively. Soleus weight decreased in both groups. Heat shock protein 72 levels in the plantaris of the HU + TEN, HU + DEN, and HU + TEN + DEN groups were 31, 25, and 30% lower than CON, respectively (P < 0.05). Plantaris weight decreased in the HU + DEN and HU + TEN + DEN, but not in the HU + TEN group. Hind limb unloading alone had little effect on the HSP72 level in either muscle. Reduced levels of HSP72 were associated with a decreased soleus (r=0.62, P < 0.01) and plantaris (r=0.78, P < 0.001) weight. These results indicate that the levels of HSP72 in both a slow and a fast rat plantarflexor are responsive to a chronic decrease in the levels of loading and/or activation and suggest that the neuromuscular activity level and the presence of innervation of a muscle are important factors that induce HSP72 expression.
测定了热休克蛋白72（HSP72）在应对涉及慢性机械卸载和去神经支配的肌肉萎缩诱导性扰动时的表达变化。成年雄性Wistar大鼠被随机分配到久坐笼养对照组（CON）、后肢卸载组（HU，通过尾部悬吊）、HU加跟腱切断术组（HU + TEN）、HU加去神经支配组（HU + DEN）或HU + TEN + DEN组。跟腱切断术和去神经支配分别涉及切断跟腱和切除一段坐骨神经。5天后，HU + DEN组和HU + TEN + DEN组比目鱼肌中的HSP72水平分别比CON组低42%（P < 0.05）和53%（P < 0.01）。两组比目鱼肌重量均下降。HU + TEN组、HU + DEN组和HU + TEN + DEN组跖肌中的HSP72水平分别比CON组低31%、25%和30%（P < 0.05）。HU + DEN组和HU + TEN + DEN组跖肌重量下降，但HU + TEN组未下降。单独后肢卸载对两种肌肉中的HSP72水平影响很小。HSP72水平降低与比目鱼肌（r = 0.62，P < 0.01）和跖肌（r = 0.78，P < 0.001）重量下降有关。这些结果表明，慢肌和快肌大鼠跖屈肌中的HSP72水平对负荷和/或激活水平的慢性降低有反应，并表明神经肌肉活动水平和肌肉的神经支配存在是诱导HSP72表达的重要因素。
