Osawa K, Maeda N, Kumegawa M, Masuda T
Shika Kiso Igakkai Zasshi. 1989 Apr;31(2):198-210. doi: 10.2330/joralbiosci1965.31.198.
Effects of lidocaine-HCl on extrafusal muscle fibers in the masseter muscle of developing mice were studied histologically and morphometrically. In the affected region, many extrafusal muscle fibers were circular and smaller in diameter than unaffected extrafusal muscle fibers, and the SDH activity of the affected fibers was very irregular. In lidocaine-HCl injected groups, the ratios of extrafusal muscle fibers with central nuclei to total extrafusal muscle fibers were higher than those in the saline solution-injected groups. The diameters of extrafusal muscle fibers in the masseter muscle treated with lidocaine-HCl were smaller than those in the saline solution-injected groups. These changes in the muscle with lidocaine-HCl continued for 45 days after a single injection. Five injections of lidocaine-HCl into developing mice caused long-term degeneration of the masseter muscle. Thus, the present study suggests that a local anesthetic agent caused degeneration of immature muscle fibers of the masseter muscle in developing mice and may result in long-term decrease of masticatory capacity. Therefore, lidocaine-HCl may inhibit the synchronized development of masticatory organs in developing animals.
采用组织学和形态测量学方法，研究盐酸利多卡因对发育中小鼠咬肌梭外肌纤维的影响。在受影响区域，许多梭外肌纤维呈圆形，直径小于未受影响的梭外肌纤维，且受影响纤维的琥珀酸脱氢酶（SDH）活性非常不规则。在盐酸利多卡因注射组中，有中央核的梭外肌纤维与总梭外肌纤维的比例高于生理盐水注射组。用盐酸利多卡因处理的咬肌中梭外肌纤维的直径小于生理盐水注射组。单次注射盐酸利多卡因后，肌肉的这些变化持续45天。对发育中小鼠进行五次盐酸利多卡因注射会导致咬肌长期退变。因此，本研究表明，局部麻醉剂会导致发育中小鼠咬肌未成熟肌纤维退变，并可能导致咀嚼能力长期下降。所以，盐酸利多卡因可能会抑制发育中动物咀嚼器官的同步发育。
