亚甲蓝对不同时期脓毒症大鼠心、肺功能的影响

目的 探讨亚甲蓝(MB)在大鼠脓毒症不同时期对心、肺功能的影响及其作用机制.方法 将56只SD大鼠随机分为早期组和晚期组.两组再分别分为假手术组(S组)、脓毒症组(CLP组)、亚甲蓝组(MB组),每组8只.使用盲肠结扎穿孔法(CLP)制作脓毒症模型.造模成功后在早期(造模后10 h,早期组)与晚期(造模后20 h,晚期组)分别给予MB 10 mg/kg治疗,10～12 h后测量大鼠血压、血气及血清一氧化氮(NO)水平.取心、肺组织做组织病理学检测.结果 CLP组和MB组大鼠的血压在脓毒症不同时期均较S组降低,差异有统计学意义(P<0.05).CLP组和MB组的MAP变化值在早期及晚期和S组比较变化幅度偏低,差异有统计学意义(P<0.05).CLP组和MB组的酸碱度(pH)在脓毒症晚期明显降低,差异有统计学意义(P<0.05).氧分压(PO2)、血氧饱和度(SpO2)在脓毒症不同时期均较S组降低,差异有统计学意义(P<0.05).CLP组和MB组在早期和晚期的NO值均较S组明显增高,差异有统计学意义(P<0.05).晚期MB组和CLP组比较,NO值明显降低,差异有统计学意义(P<0.05).早期CLP组心、肺损伤较S组严重.晚期CLP组心、肺损伤较S组和早期CLP组严重.MB治疗后未明显改善损伤.结论 MB可明显改善脓毒症晚期大鼠的低血压,MB对脓毒症各期血气值影响不大.脓毒症不同时期使用MB治疗对组织损伤程度影响不大.

Effects of methylene blue on heart and lung function of septic rats in different periods

Objective To study the effects of methylene blue(MB) on heart and lung function of septic rats in different periods and investigate the mechanism of MB.Methods Fifty six SD rats were randomly divided into early and late group.The two groups were divided into sham operation group(S group,n=8),the sepsis group(CLP group,n=8),MB group(n=8).Model of sepsis was made using the cecal ligation and puncture(CLP).After the the success of model,10 mg/kg methylene blue was given at early(10 h,early group) and late(20 h,late group) stage.10~12 h later,blood pressure,arterial blood gas parameters and serum level of nitric oxide(NO) were measured.Heart and lung tissues were tested by histopathology.Results The blood pressure reduced in CLP group and MB group compared with S group,the difference was statistically significant(P<0.05).The value changes of MAP was lowed in CLP group and MB group compared with S group,the difference was statistically significant(P<0.05).In CLP group and MB group,pH was significantly reduced at the late stage of sepsis,the difference was statistically significant(P<0.05).Both PO2 and SpO2 of CLP group and MB group declined in the period of sepsis,the difference was statistically significant(P<0.05).MB reduced serum level of NO significantly in the late MB group,the difference was statistically significant(P<0.05).The heart and lung injury in early CLP group was more serious compared with S group.The heart and lung injury in late CLP group was more serious compared with S and early CLP group.The treatment of MB had little effect on the degree of tissue damage.Conclusion MB can significantly improve hemodynamic in late septic rats,MB was no effect on blood gas values,the treatment of MB has little effect on the degree of tissue damage.