异丙酚对内脏痛大鼠海马c—fosmRNA表达的影响

Effect of propofol on expression of c-fos mRNA in hippocampus in rats with visceral pain

目的探讨异丙酚对内脏痛大鼠海马c-fosmRNA表达的影响。方法健康清洁级雄性sD大鼠30只，体重180～240g，采用随机数字表法，将大鼠随机分为3组（n=10）：内脏痛组（VP组）经尾静脉脉注射0．9％生理盐水；异丙酚7．5mg／kg组（P，组）和异丙酚75．0mg／kg组（R组）分别经尾静脉注射异丙酚7．5和75．0mg／kg。采用直肠扩张法制备内脏痛模型。于给药前后测定痛阈，将引起大鼠腹壁明显收缩变平的最小扩张气囊内压作为痛阈；痛阈测定结束处死大鼠，提取海马组织，采用RT—PCR法测定c—losmRNA的表达水平。结果与vP组比较，P1组和P2组痛阈升高，海马c—losmR．NA表达下调（P〈0．05）；与P1组比较，P2组痛阈升高，海马c—losmRNA表达下调（P〈0．05）。结论异丙酚可下调大鼠海马c—losmRNA的表达从而减轻内脏痛。

Objective To investigate the effect of propofol on the expression of c-tos mRNA in hippocam- pus in rats with visceral pain （VP）.Methods Thirty male Sprague-Dawley rats, weighing 180-240 g, were ran- domly divided into 3 groups （n = 10 each） ： VP group, propofol 7.5 mg/kg group （group P1 ） and propofol 75.0 mg/kg group （group P2 ）. 0.9 % normal saline was injected intravenously via the caudal vein in group VP. Propo- fol 7.5 and 75.0 mg/kg were injected intravenously via the caudal vein in groups P1 and P2 , respectively. VP was produced by colorectal distension in anesthetized rats. The threshold of VP was assessed by the intra-balloon pres- sure which was limited to 100 mm Hg to avoid damage to intestine before and after administration. The rats were sacrificed after measurement of the pain threshold, their brains were removed and hippocampi were isolated tor de- termination of the expression of c-los mRNA by RT-PCR.Results Compared with group VP, the threshold of VP was significantly increased and the expression of c-los mRNA in hippocampus was down-regulated in groups P1 and P2 （ P 〈 0.05） . The threshold of VP was significantly higher and the expression of c-los mRNA in hippocampus was lower in group P2 than in group P1 （ P 〈 0.05） . Conclusion Propoibl can reduce VP through down-regulating the expression of c-los mRNA in hippocampus in rats.