右美托咪定对热射病大鼠肝肾功能损伤的保护效应

The protective effects of dexmedetomidine on the liver and kidney injury in heat stroke rats

目的：探讨右美托咪定对热射病大鼠肝肾功能损伤及炎症反应的影响。方法48只成年雄性SD大鼠随机分为3组：对照组（ C组）、热射病组（ HS组）、右美托咪定组（ Dex组），每组16只。将HS组与Dex组大鼠暴露于（40．0＆#177;0．5）℃高温环境建立热射病模型，分别于热应激终点后即刻给予生理盐水和右美托咪定（25μg／kg）。分别于给药后1 h（T1）、6 h（T6）检测血清谷丙转氨酶（ALT）、谷草转氨酶（AST）、肌酐（Cr）、尿素氮（BUN）水平及白细胞介素－1β（IL－1β）、白细胞介素－6（IL－6）、肿瘤坏死因子－α（TNF－α）水平。结果与C组比较，HS组大鼠血清肝肾功能损伤标记物ALT、AST、BUN、Cr水平及炎性细胞因子IL－1β、IL－6、TNF－α水平在T1、T6两时间点均升高（ P＜0．05）；与HS组比较，Dex组大鼠血清ALT、AST、BUN、Cr、IL－1β、IL－6、TNF－α水平在T1、T6两时间点均降低（P＜0．05）。结论右美托咪定可以降低热射病大鼠血清炎性细胞因子水平，减轻肝肾功能损伤。

Objective To explore whether dexmedetomidine could attenuate heat -induced liver and kidney injury in rats and the possible mechanism .Methods Forty eight male anesthetized SD rats were randomly divided into three groups （n=16）：control group（group C）, heat stroke model group （ group HS ） and dexmedetomidine group （ group Dex ） .The model and dexmedetomidine groups were subjected to heat stress （40.0 ±0.5）℃ to induce heat stroke.A bolus injection of normal saline or dexmedetomidine（25 μg/kg） was administrated intraperitoneally immediately after the onset of heat stroke.Blood sampling was done 1 h（T1） and 6 h（T6） after injection, serum concentrations of alanine aminotransferase （ALT）, aspartate aminotransferase（AST）, creatinine （Cr）, urea nitrogen（BUN）, interleukin-1β（ IL -1β） , interleukin -6 （ IL -6 ） and tumor necrosis factor -α（ TNF -α） were measured.Results Compared with group C, the levels of liver and kidney injury markers （ALT, AST, BUN, Cr） and inflammatory cytokines （ IL-1β, IL-6, TNF-α） in serum were increased in group HS （P〈0.05）;compared with group HS, the concentrations of ALT, AST, BUN, Cr, IL-1β, IL-6 and TNF-αwere decreased in group Dex （P〈0.05）.Conclusion Systemic delivery of dexmedetomidine at the time point of onset of heat stroke may ameliorate the liver and kidney injury by regulating inflammation and decreasing the inflammatory cytokines .