右美托咪定对大鼠体外循环期间炎性因子、S100β和NSE的影响

目的 探讨不同剂量右美托咪定(Dex)对大鼠体外循环(CPB)脑损伤的脑保护作用.方法 采用随机数字表法将体重250～ 350 g、健康成年SD大鼠40只分为4组(n=10):假手术组(S组)、CPB组(C组)、DexⅠ组(DⅠ组)和DexⅡ组(DⅡ组).S组仅行动静脉穿刺置管术,DⅠ组、DⅡ组和C组行CPB转流2h,S组和C组静脉泵注与DⅡ组相同容量的生理盐水.DⅠ组在CPB前10 min静脉泵注Dex 2.5 μg/kg负荷剂量,随后以2.5 μg/(kg·h)的速度静脉输注,CPB转流2h;DⅡ组Dex负荷剂量为5 μg/kg,静脉输注速度为5μg/(kg·h).于CPB前(T0)、CPB 1 h(T1)、CPB 2 h(T2)时采集静脉血,测定血浆中白细胞介素(IL)-6、IL-10、S100β和神经元特异性烯醇化酶(NSE)的浓度.结果 与S组比较,C组T1、T2时点血浆IL-6、IL-10、S100β和NSE升高(P＜0.05);与C组比较,DⅠ组T2时点血浆IL-6、S100β降低(P＜0.05),DⅡ组T1、T2时点血浆IL-6、S100β降低(P＜0.05),DⅠ组和DⅡ组T1、T2时点血浆NSE降低(P＜0.05);与DⅠ组比较,DⅡ组T1时点血浆S100β降低(P＜0.05),DⅡ组T2时点血浆NSE降低(P＜0.05).结论 Dex可以剂量依赖性地降低S100β和NSE水平,有脑保护作用,其机制可能与抑制炎性反应有关.

Effects of dexmedetomidine on inflammatory cytokines,S100β and NSE in rats undergoing cardiopulmonary bypass

Objective To evaluate the effects of dexmedetomidine (Dex) on inflammatory cytokines,S100β and NSE in rats undergoing cardiopulmonary bypass.Methods Forty Sprague-Dawley rats,weighing 250 ～350 g,were randomly divided into 4 groups (n =10 each) using a random number table,sham operation group (Group S),cardiopulmonary bypass group (Group C),Dex Ⅰ group (Group D Ⅰ),and Dex Ⅱ group (Group D Ⅱ).Rats in the Group G received no CPB procedure.CPB rat model was established in Group C,Group D Ⅰ and Group D Ⅱ.In Group D Ⅰ,Dex was infused at a rate of 2.5 μg/(kg · h) for 2 h during CPB after a loading dose of Dex by 2.5 μg/kg.In group D Ⅱ,Dex was infused at a rate of 5 μg/(kg · h) for 2 h during CPB after a loading dose of Dex by 5 μg/kg.Before CPB (T0),1 h after CPB (T1),and 2 h after CPB (T2),venous blood samples were collected for detection of plasma concentrations of interleukin 6 (IL-6),interleukin 10 (IL-10),S100β and NSE in using ELISA.Results Compared with Group S,concentrations of IL-6,IL-10,S100β and NSE at T1 and T2 were significantly increased in Group C (P ＜ 0.05).Compared with Group C,the concentrations of IL-6 and S100β at T2 were significantly reduced in Group D Ⅰ (P ＜0.05),as the concentrations of IL-6 and S100β at T1 and T2 were significantly decreased in Group D Ⅱ (P ＜ 0.05).Meanwhile,the concentrations of NSE at T1 and T2 were significantly reduced in Group D Ⅰ and Group D Ⅱ (P ＜0.05).Compared with Group D Ⅰ,the concentration of S100β at T1 was significantly reduced in Group D Ⅱ (P ＜ 0.05),and the concentration of NSE at T2 was significantly reduced in Group D Ⅱ (P ＜ 0.05).Conclusion Dex can attenuate the cerebral injury followed by CPB through inhibiting the inflammatory responses.And there is a certain correlation between the effect of cerebral protection and the doses of Dex.