卡巴胆碱减轻肠缺血/再灌注大鼠中性粒细胞活化和多器官损伤

目的探讨胆碱能激动剂——卡巴胆碱对肠缺血/再灌注大鼠中性粒细胞活化的影响及其对脏器功能的保护作用。方法雄性Wistar大鼠随机分为假手术组(N)、肠缺血/再灌注组(I/R)及卡巴胆碱组(Car)。夹闭肠系膜上动脉45min后恢复灌流制成肠I/R模型;卡巴胆碱组在肠缺血15min后经幽门注射卡巴胆碱(100μg/kg体质量)。于缺血45min(I45)、再灌注1h(R1)、2h(R2)、6h(R6)取肠系膜上静脉血进行中性粒细胞(PMN)计数、测定PMN呼吸爆发强度、检测反映脏器功能的血浆酶学指标以及肠和肺组织髓过氧化物酶(MPO)活性。结果肠缺血45min,PMN计数下降,再灌注后逐渐回升,至R6时达高峰。Car组PMN计数在R2和R6时显著低于I/R组大鼠;PMN呼吸爆发强度的变化规律与PMN计数一致。相关分析表明,PMN化学发光峰值变化和血PMN计数的变化呈正相关(r=0.748,P<0.05)。大鼠小肠组织MPO活性在肠缺血和再灌注均升高(P<0.05),R6达最高;Car组小肠MPO活性在肠I/R各时间点均显著低于I/R组(P<0.05～P<0.01)。肺组织MPO活性在肠缺血期降低,再灌注后逐渐升高,在R6时MPO活性达高峰(P<0.01),而此时Car组大鼠肺组织MPO活性仅为I/R组的31%(P<0.01),接近N组。GI/R组大鼠血浆天冬氨酸转氨酶(AST)、丙氨酸转氨酶(ALT)、肌酐(Cr)、肌酸激酶-同工酶(CK-MB)在肠缺血后均升高,R2时达峰值(P<0.01),R6时仍高于N组(P<0.05)。Car组大鼠各指标在再灌注后均较I/R组同时相点低,以R2组效果最明显(P<0.01)。结论卡巴胆碱能显著抑制PMN活化,减轻GI/R引起的多脏器功能损伤。

Carbachol ameliorates neutrophil activation and multiple organ injury in gut ischemia-reperfusion rats

Objective To investigate the effect of carbachol, a cholinergic agonist, on neutropbil （PMN） activation and organ dysfunction in rats with gut ischemia-reperfusion （GI/R） injury. Methods Adult Wistar male rats were randomly divided into nomlal （N）, gut ischemia-reperfusion （I/R） and gut ischemia-reperfusion plus carbachol （Car） groups. GI/R was achieved by clipping superior mesentery artery （ischemia） for 45 min with subsequent reperfusion. The eholinergic agonists carbachol （100 μg/kg BW） or saline-vehicle were administered to rats of Car and N groups respectively via pylorus at 15 min after isehemia. At 45 min of gut isehemia （I45）, I h, 2 h and 6 h of reperfusion （R1, R2 and R6）, PMN counts and PMN respiratory burst in superior mesentery venous blood were measured. Plasma alanine transaminase （ALT） creatine phosphate kinase activities （CK-MB）, and creatinine concentration （Cr） were determined. Myeloperxidase （MPO） activity in lung and intestinal tissues was assessed. Results in I/R rats, PMN counts in the blood decreased when gut ischemia for 45 min, increased gradually following reperfusion, and peaked at reperfusion 6 h. In Car rats, PMN counts were lower than those in I/R rats at reperfusion 2 h and 6 h. The intensity of PMN respiratory burst varied with change of PMN count in a positive correlation （r=0.748, P〈0.05）. MPO activity in intestinal tissue of GI/R rats increased after gut ischemia and reperfusion （P〈0.05）, which was much higher than that of Car rats at all time points （P〈0.05-P〈0.01）, peaking at reperfusion 6 h. Change of MPO activity in I/R rats lungs was consistent with that of PMN count in the blood, which was obviously higher than that of Car rats at reperfusion 6 h （P〈 0.01）. Plasma AST, ALT, Cr and CK-MB increased in GI/R rats, higher than that in Car rats, particularly at reperfusion ：2 h （P〈0.01）. Conclusion Pharmacological modulation with carbachol demonstrated inhibition on the PMN activation and ame