Tennyson V M, Kremzner L T, Brzin M
J Neuropathol Exp Neurol. 1977 Mar-Apr;36(2):245-75. doi: 10.1097/00005072-197703000-00004.
Acetylcholinesterase (AChE) activity has been studied in normal, control and denervated muscle of rabbits by electron microscopic-cytochemistry and radiometric assay. A small amount of butyrylcholinesterase (BuChE) activity is also found in biochemical assay of unfixed muscle, but it is not demonstrable cytochemically in fixed specimens by the method used in this study. Both a soluble and particulate AChE activity are present in all specimens examined. The particulate activity is probably due to enzyme localized in the sarcotubular system and at the motor end-plate. Soluble AChE activity may represent those sites exhibiting random cytochemical end product, such as some areas of normal and denervated muscle and muscle nuclei, Schwann cells, and AChE-containing mononuclear cells in the connective tissue. There is a greater proportion of particulate than soluble AChE activity in normal and control muscle, a finding which is compatible with the well localized cytochemical sites. Four to six weeks post-denervation, there is a marked increase in extrajunctional AChE activity to peak values 15 to 30 fold above control values. The increase is accompanied by a reversal in the proportion of particulate to soluble enzyme, so that there is almost twice as much soluble as particulate AChE. There are also numerous "spots" of random cytochemical end product throughout extrajunctional muscle. The increase in levels of AChE activity, the change to predominantly soluble form, and the large numbers of new cytochemically active sites indicate that synthesis of new enzyme has taken place. Changes in AChE activity in denervated rabbit have been compared to those occurring in dystrophic mouse muscle. It has been suggested that there might be a relationship between the formation of new extrajunctional sarcoplasmic sites of AChE activity and the spread of alpha-bungarotoxin binding sites and chemosensitivity in developing and denervated muscle.
已通过电子显微镜细胞化学和放射测定法对家兔正常、对照和去神经肌肉中的乙酰胆碱酯酶（AChE）活性进行了研究。在未固定肌肉的生化测定中也发现了少量丁酰胆碱酯酶（BuChE）活性，但用本研究方法在固定标本中无法通过细胞化学方法显示。在所检查的所有标本中均存在可溶性和颗粒性AChE活性。颗粒性活性可能是由于酶定位于肌管系统和运动终板。可溶性AChE活性可能代表那些呈现随机细胞化学终产物的部位，例如正常和去神经肌肉的某些区域以及肌肉细胞核、雪旺细胞和结缔组织中含AChE的单核细胞。正常和对照肌肉中颗粒性AChE活性的比例高于可溶性AChE活性，这一发现与细胞化学定位良好的部位相符。去神经后4至6周，接头外AChE活性显著增加，达到比对照值高15至30倍的峰值。这种增加伴随着颗粒性酶与可溶性酶比例的逆转，使得可溶性AChE几乎是颗粒性AChE的两倍。在整个接头外肌肉中也有许多随机细胞化学终产物的“斑点”。AChE活性水平的增加、向主要可溶性形式的转变以及大量新的细胞化学活性位点表明已发生新酶的合成。已将去神经家兔中AChE活性的变化与营养不良小鼠肌肉中发生的变化进行了比较。有人提出，AChE活性新的接头外肌浆位点的形成与发育中和去神经肌肉中α-银环蛇毒素结合位点的扩散及化学敏感性之间可能存在关系。
