低氧复合氰化钠中毒对大鼠肺的损伤效应

目的探讨低氧复合氰化钠(NaCN)中毒对大鼠的肺损伤效应。方法以低压氧舱模拟4 000m低氧环境。72只大鼠随机分为海拔308m中毒组和海拔4 000m中毒组。皮下注射3.6mg/kg NaCN,分别于0、0.5、1、2、4、6h取肺组织和支气管肺泡灌洗液(BALF),测定超氧化物歧化酶(SOD)、谷胱甘肽-过氧化物酶(GSH-PX)活力,丙二醛(MDA)、谷胱甘肽(GSH)、伊文思蓝(EB)含量,酸性磷酸酶(ACP)、乳酸脱氢酶(LDH)及碱性磷酸酶(AKP)的活性。结果NaCN中毒后BALF中LDH、ACP及AKP活性明显增高,0.5h最高。低氧(海拔4 000m)复合NaCN中毒大鼠BALF中LDH、ACP及AKP活性明显高于同一时相点单纯(海拔308m)NaCN中毒大鼠。低氧复合NaCN中毒能引起肺组织和BALF中的GSH含量、SOD和GSH-PX活力下降,并引起MDA含量增加,各指标的变化幅度远大于单纯NaCN中毒的效应。结论在低氧条件下NaCN的细胞毒性作用增强,肺损伤程度加重,严重影响大鼠肺的氧化应激水平和肺血管通透性。

Lung injury of rats induced by combined hypoxia and NaCN intoxication

Objective To explore the effects of oxidative stress and pulmonary vascular permeability on lung injury in rats treated with sodium cyanide(NaCN) and /or hypobaric hypoxia.Methods A total of 72 male SD rats were randomly divided into 2 groups: the NaCN intoxicated group in 308m altitude and the hypobaric hypoxia combined NaCN intoxicated group in 4 000m high altitude.The animals for the experiment of hypoxia were processed in an artificial hypobaric chamber to simulate the designated high altitude hypoxia(4 000m,61kPa).NaCN was injected subcutaneously to the rats in the both groups at the dosage of 3.6mg/kg.Broncho-alveolar lavage fluid(BALF) and lung tissues were prepared at the time points of 0,0.5,1.0,2.0,4.0 and 6.0h.The activity of SOD,GSH-PX,ACE,LDH,AKP and the content of MDA,GSH,Evan's blue(EB) were detected by spectrophotometric method.Results Combined acute hypobaric hypoxia and NaCN intoxication produced a significant increasing effect on EB content in the rats.The activity of ACE,LDH and AKP in BALF,and the contents of MDA in BALF and lung tissue reached the highest value at 0.5h preparation at the combined hypobaric hypoxia and NaCN intoxicated group,but they were still higher than that of control group(NaCN intoxicated only);correspondingly the activity of SOD,GSH-PX,content of GSH in lung tissue and BALF reached the lowest value at 0.5h preparation at the combined hypobaric hypoxia and NaCN intoxicated group,but they were still lower than that of control NaCN intoxicated group.Conclusion The results suggest that under the condition of hypoxia,NaCN intoxication may produce severe harmful effects on the lungs,increase the pulmonary vascular permeability,and cause severe interference on to the oxidative stress level.