急性肺水肿大鼠肺组织中IL-6,SOD和MDA的变化

目的探讨急性缺氧致大鼠急性肺水肿模型肺组织中丙二醛(malondialdehyde,MDA)、超氧化物歧化酶(superoxide dismutase,SOD)和白细胞介素-6(Interleukin 6,IL-6)的变化及其意义。方法成年Wistar大鼠50只,随机分为A组(正常组)、B组(急性肺水肿模型,缺氧24 h)、C组(急性肺水肿模型,缺氧48 h),D组(急性肺水肿模型,缺氧72 h)和E组(急性肺水肿激素治疗组,缺氧72 h)。对B,C,D,E组大鼠腹腔内注射6%氯化氨建立急性肺水肿模型,E组在注入6%氯化氨30 min后经尾静脉给药,给予地塞米松6.0 mg/kg。造模成功后的24 h,48h,72 h,分别处死4组大鼠,分离大鼠血浆,摘取大鼠肺脏,制备10%肺组织匀浆,用ELISA检测肺组织中MDA、SOD,IL-6和血浆中IL-6的含量和活性。结果 B,C,D三组可见大鼠肺组织水肿明显,湿重明显增加,与A组相比,差异有统计学意义(P0.05)。A组大鼠肺组织无明显充血水肿,肺组织形态大致正常。B,C,D大鼠模型肺组织充血水肿,肺组织间质间隙、肺泡和细支气管内充满含有蛋白质的液体,肺泡内有透明膜形成。且D组大鼠肺组织充血水肿最为明显。而E组大鼠全肺组织水肿普遍较轻,HE染色显示E组大鼠肺组织肺泡融合,间隔较小,水肿液大多已吸收,肺泡内散在少量嗜伊红液体。B组与A组比较,肺组织中MDA,IL-6升高、SOD降低,但差异无统计学意义(P0.05),随着肺水肿时间的延长,C,D组大鼠肺组织中MDA升高,SOD降低,血浆中的IL-6升高,和A组相比变化明显,差异有统计学意义(P0.05)。和D组相比,E组大鼠肺组织中MDA降低,SOD升高,血浆中的IL-6降低,差异有统计学意义(P0.05)。结论急性肺水肿的发生和氧化应激有关,机体抗氧化能力降低、自由基增加是肺水肿发生的重要机制,肺组织中IL-6,SOD和MDA含量对病情变化有指导意义。

Study on SOD, MDA and IL-6 in a rat model of acute pulmonary edema

Objective To investigate Interleukin 6(IL-6),superoxide dismutase (SOD),malondialdehyde (MDA) in lung tissues of a rat acute pulmonary edema model induced by acute hypoxia. Methods 50 adult Wistar rats were randomly divided into group A (normal),B (acute pulmonary edema,hypoxia for 24 h),C (acute pulmonary edema,hypoxia for 48h),D(acute pulmonary edema,hypoxia for 72 h) and E (dexamethasone treatment,hypoxia for 72h). The model of acute pulmonary edema was established by intraperitoneal injection with 6% ammonium chloride. In group E, dexamethasone (6mg/kg) was injected in tail vein following intraperitoneal injection of 6% ammonium chloride. The rats were killed 24(group B), 48 (C) and 72 hours(D&E) later. Plasma was isolated and lungs were removed. MDA,SOD in lung tissues and IL-6 in plasma were analyzed by ELISA. Results The wet weight of lung tissues were significantly increased in group B, C and D compared to group A(P<0.05). The lung tissues of group A had no obvious congestion and edema,and the morphology of lung tissues was normal(P>0.05). Pulmonary edema,interstitial spaces and alveolar filled fluid can be seen in group B,C,D and transparent membrane formed within alveoli. The lung tissue congestion and edema in group D were the most obvious(P<0.05). The above changes obviously improved in group E. Compared with group A,MDA,IL-6 increased and SOD decreased in lung tissues of group C and D. Compared with group D, MDA was decreased and SOD was increased in lung tissues of group E and IL-6 was also decreased significantly in plasma(P<0.05). Conclusion The occurrence of acute pulmonary edema related to oxidative stress and decreased antioxidant capacity. Increased free radical is an important mechanism of pulmonary edema. SOD,MDA and IL-6 in the lung tissue may be indexes for the prognosis.