肺内源性急性肺损伤大鼠肾上腺皮质功能的变化和意义

目的探讨大肠杆菌导致的肺内源性急性肺损伤(ALI)模型大鼠肾上腺皮质功能的变化。方法Wistar大鼠气管注射3ml/kg大肠杆菌混悬液(4.4～5.6)×1012CFU/L],制作大鼠肺内源性ALI/急性呼吸窘迫综合征(ARDS)模型,存活大鼠随机分为三组,于滴入大肠杆菌混悬液术后6h(n=10)、24h(n=10)、36h(n=10)3个时间点进行观察。每个时间点各8只大鼠作为对照(NS组,气管注射0.9%盐水3mL/kg)。各组分别于术后6、24、36h3个时间点经气管切开插管机械通气,颈总动脉插管监测其血压、血气,取血,PaO2/FiO2<300mmHg(39.9kPa)为ALI,PaO2/FiO2<200mmHg(26.6kPa)为ARDS,符合上述标准的模型大鼠纳入实验。给予小剂量ACTH作ACTH刺激试验,应用ELISA法测定血清中皮质酮、ACTH含量。结果血浆ACTH水平在模型组大鼠各时间点均高于对照组(P均<0.01),24h达峰值(P<0.01)。模型组6h、24h时间点皮质酮较对照组明显升高(P<0.01,P<0.05),36h模型大鼠皮质酮低于对照组(P<0.05)。模型组6h皮质酮达...

Adrenal dysfunction in rats with pulmonary acute lung injury

Objective To study the adrenal function in rats with pulmonary acute lung injury (ALI) induced by Escherichia coli (0111B4) . Methods ALI rat model was induced by intratracheal injection of E.coli (3 ml/kg,0111B4,(4.4-5.6) x 10~(12) CFU/L).ALI rats were then randomly divided into three groups,and each group had 10 rats.Mechanical ventilation was applied at three time points,6 hours,24 hours,and 36 hours after injection At each time point 8 rats were used as control with saline administered intratracheally.The plasma ACTH and corticosterone levels were measured after stimulated by 100 μg porcine ACTH.Results Compared with control group,the model group had a higher level of plasma ACTH at each time point (P < 0.01).The plasma ACTH level reached the peak at 24 hours.The model group had a higher level of plasma corticosterone at 6 hours (P < 0.01) and 24 hours (P <0.05),but had a lower level of plasma corticosterone at 36 hours (P < 0.05).The plasma corticosterone level reached the peak at 6 hours in model group,which was higher than 24 hours (P < 0.05).After stimulated by ACTH,the increased levels of corticosterone were lower in model group than those in control group (6 hours,P < 0.05; 24 hours and 36 hours,P < 0.01).Conclusions Adrenal dysfunction may occur at early stage of ALI in rats.With the disease developed,adrenal response to ACTH decreased.Low dose corticotrophin-stimulated test could evaluate adrenal function in rats with pulmonary ALI induced by Escherichia coli (O111B4).