二甲基亚砜抑制吗啡诱导热痛觉过敏的实验研究

Study of inhibition of dimethyl sulfoxide on morphine-induced thermal hyperalgesia

目的观察二甲基亚砜(DMSO)对吗啡诱导的热痛觉过敏及其对脊髓背角肿瘤坏死因子(TNF-α)表达的影响。方法 32只SD大鼠随机分为4组,A组(生理盐水+吗啡组)、B组(10%DMSO 5 mL/kg+吗啡组),C组(10%DMSO 5 mL/kg+生理盐水组)和D组(生理盐水组)。各组大鼠分别每d3PM腹腔注射生理盐水或DMSO,30 min后皮下注射吗啡或生理盐水。观察注药前1d,注药后3 d、6 d、10 d大鼠热刺激撤足潜伏期的变化及脊髓背角TNF-α表达情况。结果与注药前相比,A组注药后3 d开始热刺激撤足潜伏期缩短,10 d进一步缩短(P<0.01)。与A组比较,B组注药后6 d、10 d热刺激撤足潜伏期延长有统计学意义(P<0.01)。A组脊髓背角TNF-α表达较其它组增高(P<0.01)。B组TNF-α的表达较A组低,较D组高有统计学意义(P<0.01)。结论 DMSO可能通过抑制脊髓背角TNF-α的产生而减轻吗啡诱导的热痛觉过敏。

Objective To explore the influence of dimethyl sulfoxide （DMSO） on morphine- induced thermal hyperalgesia and the expression of tumor necrosis factor-alpha （TNF-ct） in the spinal cord dorsal horn. Methods Thirty-two SD rats were randomly divided into 4 groups, group A （saline ＋ morphine group）, group B （10% DMSO 5 mL/kg ＋ morphine group）, group C （10% DMSO 5 mL/kg ＋ normal saline group） and group D （saline group）. In each group, morphine or normal saline was injected subcutaneously 30 min after I.P normal saline or DMSO at 3 PM respectively. Paw withdrawal thermal latency （PWTL） were measured at 1 day before injection and 3, 6, 10 days after injection respectively and the expression of TNF alpha on spinal cord dorsal horn was detected. Results Compared with 1 day before injection, the PWTL of group A became shortened from 3 days after injection, and it further shortened at 10 day after injection respectively （P〈0.01）. There were significant differences in the shortening of PWTL between group A and group B 6 and 10 days after injection. The spinal dorsal horn TNF alpha expression of group A was higher than other groups （P〈 0.01 ）. TNF alpha expression of group B were lower than which of group A and higher than which of group D. Conclusion DMSO can reduce morphine-induced thermal hyperalgesia by inhibiting spinal dorsal horn TNF alpha generation.