Davis H L, Bressler B H, Jasch L G
Department of Anatomy, McGill University, Montreal, Quebec, Canada.
Exp Neurol. 1988 Feb;99(2):474-89. doi: 10.1016/0014-4886(88)90164-1.
Certain morphological, biochemical, and physiological parameters were assessed in fast-twitch muscles of 6-week-old mice with unilateral hindlimb denervation for 4 weeks. Some of the mice received daily injections (i.p.) of nerve extract throughout the period of denervation. Values from treated and untreated denervated muscles were compared with each other and with those from contralateral, innervated controls. The cross-sectional areas of denervated types IIA and IIATy muscle fibers were 45% and 28% greater, respectively, in muscles of treated than of untreated mice, which resulted in greater maximal tetanic tension. Injection with nerve extract did not influence the postdenervation reduction of phosphorylation of myosin light chain 2-fast nor the loss of posttetanic twitch potentiation, two parameters thought to be related. Denervation produced a significant decrease in relative content of cytosolic parvalbumin; however, this change was completely prevented by administration of nerve extract. This latter finding correlated with the amelioration of greater than 50% of the postdenervation prolongation of half-relaxation time of the twitch in treated than in untreated muscles. More than half of the prolongation of time-to-peak of the twitch was also prevented in denervated muscles of treated than of untreated mice.
对单侧后肢去神经支配4周的6周龄小鼠的快肌进行了某些形态学、生物化学和生理学参数评估。部分小鼠在去神经支配期间每天腹腔注射神经提取物。将处理组和未处理组去神经肌肉的值相互比较，并与对侧有神经支配的对照组的值进行比较。在处理组小鼠的肌肉中，去神经的IIA型和IIATy型肌纤维的横截面积分别比未处理组小鼠的大45%和28%，这导致了更大的强直收缩张力。注射神经提取物并未影响去神经后肌球蛋白轻链2-快的磷酸化减少，也未影响强直后抽搐增强的丧失，这两个参数被认为是相关的。去神经支配导致胞质小白蛋白的相对含量显著降低；然而，通过给予神经提取物，这种变化完全得到了预防。后一项发现与处理组肌肉中去神经后抽搐半松弛时间延长超过50%的改善相关。在处理组小鼠的去神经肌肉中，抽搐峰值时间延长的一半以上也得到了预防，而未处理组小鼠则没有。
