急性肺损伤兔ACE、ET-1变化及美洛昔康的拮抗作用

Changes of ACE and ET-1 in endotoxin-induced acute lung injury and antagonistic effects of meloxicam in rabbits

目的:观察内毒素致兔急性肺损伤(ALI)时血清血管紧张素转换酶(ACE)活性和肺组织内皮素-1(ET-1)含量变化及美洛昔康对急性肺损伤干预作用的机制。方法:将24只日本大耳白兔随机分为对照组、致伤组、美洛昔康干预组。用内毒素(700μg/kg)一次性静脉注射方法复制兔ALI模型,应用美洛昔康(2.5 mg/kg)进行干预。分别检测血清ACE活性和肺组织ET-1含量。结果:致伤后0.5 h,血清ACE活性明显升高,1 h时血清ACE活性达到峰值。美洛昔康组血清ACE活性也出现升高,但明显低于致伤组。致伤组肺组织ET-1高于对照组(P<0.01),美洛昔康干预组肺组织ET-1明显低于致伤组(P<0.01)。结论:美洛昔康可以抑制血清ACE活性和降低肺组织中ET-1的含量,对内毒素所致ALI具有一定的拮抗作用。

Objective ：To investigate the changes of serum angiotensin converting enzyme （ACE）activity and pulmonary endothelin-1 （ET-1） content in rabbits with acute lung injury （ALI） induced by endotoxin and the effects of meloxicam, so as to explore the protective mechanism of meloxicam. Methods：Twenty four Japanese flap-eared white rabbits were randomly assigned to three groups ： control group, endotoxin -treated group and meloxicam -treated group. ALI models of rabbits were replicated with intravascular endotoxin injection （700 μg/kg weight）, meloxicam （2.5 mg/kg weight） was intravascularly injected in treatment group. We measured serum ACE activity and pulmonary ET-1 content in every group. Results：In endotoxin-treated group, serum ACE activity increased at 0.5h,and reached a peak at lh. In meloxicam-treated group, ACE activity in serum also increased,while serum ACE activity was significantly lower than that in endotoxin-treated group. In endotoxin - treated group, the levels of ET-1 in lung tissue were significantly higher than those in control group（P 〈0.01 ）. In meloxicam-treated group, the levels of ET-1 in lung tissue were significantly lower than those in endotoxin -treated group（P 〈 0.01 ）. Conclusion： Meloxicam can inhibit serum ACE activity and down-regulate the levels of ET in lung tissue, which pesseses some protective effects on ALI induced by endotoxin in rabbits.