[Effect of mailuoning injection on calcitonin gene-related peptide expression in facial nerve of rabbits with facial spasm].

OBJECTIVE

To investigate the mechanism of Mailuoning injection (MLN) in protecting facial nerve from injury.

METHODS

The New Zealand white rabbit model with facial spasm was established by compressing superficial temporal artery to make artificial demyelinated lesion of the main peripheral facial nerve trunk. The successful establishment was confirmed by using electrophysiological technique to determine abnormal muscle response (AMR) which is a characteristic for facial spasm. MLN was injected continuously through ear marginal vein for 2 weeks. The change of CGRP expression in facial nerve was detected by immunohistochemical technique.

RESULTS

As compared with the model group, CGRP expression in facial nerve was significantly increased in the MLN group (P <0.01), and CGRP immunoreactive positive fibers were not seen in the shamoperation group. In the model group, the facial nerve fibers degenerated obviously, myelin sheath loosened and dissociated, the turgent axons with vacuole or even completely disappeared. But the facial nerve lesion was lessened in the MLN group.

CONCLUSION

MLN has a significant protective effect on facial nerve demyelination in rabbits with facial spasm, which is closely related with its effect in improving CGRP expression in the facial nerve.