Effects of autophagy activation on the apoptosis of GABA neurons in the dorsal horn of postherpetic neu-ralgia model mice / 临床麻醉学杂志

ABSTRACT

Objective To investigate the effects of different degrees of autophagy on the apop-tosis of GABAergic neurons in spinal dorsal horn of postherpetic neuralgia model mice. Methods Forty-eight Kunming mice,approximately 6-8 weeks of age and weighing 18-22 g,were randomly divided into four groups by a random digital generator of SPSS 19.0resinotoxin+autoph-agy induction group (group PHN+Rapa),resinotoxin group (group PHN),resinotoxin+autophagy inhibitor group (group PHN+3-MA)and blank control group (group C),12 mice in each group. Group C was given no treatment,and the other groups were given intraperitoneal injection of 0.2 μg/g resiniferatoxin (RTX)to prepare PHN model.After successful model establishment,group PHN+Rapa was given Rapamycin (1 μg·kg-1·d-1),physiological saline was given to group PHN, group PHN+3-MA was given 2 μg·kg-1·d-1autophagy inhibitor 3-MA.The intraperitoneal injection was continued for 14 day.The mechanical withdrawal threshold (MWT)and the latent period of thermal withdrawal latency (TWL)were detected and the mice were killed after stability. The segments of L4-6spinal cord were extracted and the relative expressions of bcl-2,Bax and autoph-agy-associated protein LC3 were detected by western blot.Detection of the number of apoptotic cells in the spinal cord by fluorescence Tunel.The number of GABA intermediate neurons in the dorsal horn of the spinal cord was labeled by immunofluorescence.Results Compared with group C,the rel-ative expression level of Bax protein increased significantly,the LC3-II/I ratio and the number of ap-optotic cells increased significantly,the relative expression level of Bcl-2 protein and the number of GABA neurons in spinal dorsal horn were significantly reduced in other groups (P<0.05).Compared with group PHN,the LC3-II/I ratio and the relative expression level of Bax protein,the number of apoptotic cells increased significantly,the relative expression level of Bcl-2 protein and the number of GABA neurons in the spinal dorsal horn were significantly decreased of group PHN+Rapa (P<0.05).Compared with group PHN,the relative expression level of LC3-II/I ratio and Bax protein, the number of apoptotic cells decreased significantly,the relative expression level of Bcl-2 protein and the number of GABA neurons in spinal dorsal horn increased significantly of group PHN+3-MA,(P<0.05).Conclusion Over activation of autophagy may be one of the mechanisms leading to the ap-optosis of GABA neurons in the dorsal horn of the spinal cord in postherpetic neuralgia.