Abstract: Objective To study the change in the level of heat shock protein 27 in facial motor nucleus after facial nerve axotomy. Methods Thirty Wistar rats were randomized into 3 groups: experimental group, surgical control group, and blank control group, with 10 rats in each group; at the time points of pre- and 1, 2, 3, 4 days post-right facial nerve axotomy, the samples of right facial motor nucleus of 2 rats in every group were collected; the supernatant containing heat shock protein 27 from the collected tissue samples were collected and the level of heat shock protein 27 in the three different experimental groups were determined by the use of Western blotting. Results In the experimental group, the expression level of heat shock protein 27 in facial motor nucleus was significantly up-regulated on the 1st day post- facial nerve axotomy as compared with pre- facial nerve axotomy, peaked on the 2nd day post-facial nerve axotomy, declined on the 3rd day post-facial nerve axotomy, and further declined on the 4th day post-FNA, which was still higher than the expression level of pre- facial nerve axotomy; in the surgical and blank control group, there was no significant difference in the level of heat shock protein 27. Conclusion After facial nerve axotomy, the level of heat shock protein 27 was obviously up-regulated in facial motor nucleus, peaked on the 2nd day post-facial nerve axotomy, and then gradually declined on the 3rd and 4th day post-facial nerve axotomy, but still remained higher than the level of pre-facial nerve axotomy.

Key words: heat shock protein 27, facial motor nucleus, facial motor neurons