title: Effects of tetramethylpyrazine on neuronal apoptosis in the superficial dorsal horn in a rat model of neuropathic pain.
abstract: The Bennett and Xie (1988) model of chronic constriction injury (CCI) investigated the effects of tetramethylpyrazine (TMP) on neuropathic pain-associated behaviors and neuronal apoptosis in the spinal dorsal horn. Fifty-four male rats were randomly divided into sham (group S), CCI (group C) and TMP groups (group T). Each group was divided into subgroups (n = 6 in each group) according the time of sacrifice: 3 d, 7 d and 14 d. Rat sciatic nerves were unligated (group S), or the right sciatic nerve was loosely ligated (groups C and T) to produce CCI. Mechanical withdrawal thresholds (MWTs) and thermal withdrawal latencies (TWLs) were measured, and the rats were sacrificed at different time points post-operation. The L4-L6 sections of the spinal cord were removed. Apoptotic changes were evaluated using the TUNEL method. Immunohistochemistry assessed Bcl-2 and caspase-3 expression. TMP treatment increased MWT and TWL values and Bcl-2 expression, but it reduced neuronal apoptosis and caspase-3 expression in laminae I-II of the spinal dorsal horn. These results suggested that the inhibition of neuronal apoptosis via the modulation of Bcl-2 and caspase-3 proteins in the rat spinal dorsal horn contributed to TMP-induced analgesia.
authors.affiliation: Department of Anesthesiology, First Hospital, Lanzhou University, Lanzhou, Gansu, P. R. China. lengyf@lzu.edu.cn
authors.forename: Yu-Fang
authors.initials: YF
authors.lastname: Leng
authors.forename: Xiang-Mei
authors.initials: XM
authors.lastname: Gao
authors.forename: Shu-Xiu
authors.initials: SX
authors.lastname: Wang
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Xing
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008297:Male; D009437:Neuralgia / Q000473:pathology*; D009474:Neurons / Q000187:drug effects* / Q000201:enzymology; D020671:Posterior Horn Cells / Q000187:drug effects*; D011719:Pyrazines / Q000494:pharmacology*; D051381:Rats
chemical_list: D011719:Pyrazines; D053148:Caspase 3; C017953:tetramethylpyrazine