低频脉冲磁刺激对大鼠牙髓组织内降钙素基因相关肽免疫阳性神经纤维的影响

目的探讨低频脉冲磁刺激对大鼠牙髓组织内降钙素基因相关肽（CGRP）免疫阳性的神经纤维的影响。方法选择健康Sprague—Dawley大鼠15只，随机分为对照组、多次磁刺激组和单次磁刺激组，每组5只。后两组采用低频脉冲磁刺激大鼠颌面部，频率为2Hz，强度峰值为2T。多次磁刺激组每日给予1次连续30个脉冲的磁刺激，连续刺激6d；单次磁刺激组仅给予1次30个脉冲的磁刺激。取上颌磨牙制备标本，CGRP免疫组织化学染色，显微镜观察阳性神经纤维密度并进行统计学分析。结果多次磁刺激组大鼠牙根髓上段和髓角处CGRP阳性神经纤维明显增多，染色增强，与对照组比较，差异有统计学意义（P〈0．05）；而单次磁刺激组大鼠牙根髓上段和髓角处CGRP阳性神经纤维明显减少，染色变淡，与对照组比较，差异有统计学意义（P〈0．01）。结论多次连续低频脉冲磁刺激可促进牙髓组织内CGRP的表达，单次低频脉冲磁刺激可促进组织中部分CGRP释放，使其在组织中表达减少，其机制及生物学意义尚需深入探讨。

The effects of impulse magnetic stimulation on calcitonin gene-related peptide in rat dental pulp

Objective To investigate the effects of impulse magnetic stimulation (IMS) on calcitonin gene-related peptide( CGRP) in rat dental pulp. Methods Fifteen Sprague-Dawley rats were randomly divided into a control group and two experimental groups A and B. The maxillofacial regions of the rats were exposed to IMS at 2. 0 Hz and 2 T. The rats in group A were exposed to IMS once a day for 6 d, while the rats in the group B were exposed once to IMS. The expression of CGRP in maxillary molars was measured by using immunohistochemical staining. Results Compared with that in the control group, the expression of CGRP positive nervous fibers in the superior segment dental pulp and pulp horn were increased significantly in group A ( P < 0. 05 ) , but significantly decreased in group B (P < 0. 01). Conclusion The expression of CGRP in rat dental pulp could be improved by the continuous low frequency IMS, but decreased by the single IMS.