内皮素在实验性肺纤维化发生发展中的作用

Role of Endothelin in the Genesis and Progression of Pulmonary Fibrosis in Rats

目的 了解内皮素 (ET)在肺纤维化 (PF)发生发展中的作用及意义。方法 采用放射免疫法测定实验组 (博莱霉素— BLM组 )和对照组 (生理盐水组 )大鼠在实验第 1 ,3,7,1 4和 2 8d时血和支气管肺泡灌洗液 (BALF)中 ET含量 ,并采用 SP免疫组织化学方法动态观察肺组织中的 ET表达情况。结果 (1 )实验组大鼠在实验早期 ,血浆和 BALF中 ET含量均明显高于对照组。BALF以蛋白作为内部标记参考物表示 ng· L-1· g-1 ,则实验组 ET含量亦高于对照组 ,其变化量与标记前的量不成比例。 (2 ) ET与 BALF中细胞总数无相关 ,与 BALF中多形核白细胞 (PMN)及淋巴细胞呈明显正相关。 (3)实验组在 1～ 7d支气管粘膜上皮和炎性细胞 ET表达增强 ,7～ 1 4 d持续表达 ,1 4～ 2 8d高表达 ,而 型肺泡上皮细胞于 7d后出现 ET的表达增强。结论 BALF中 ET水平能反应肺泡炎的程度及病变活动性 ,可作为早期诊断的参考指标。ET参与 PF的渗出和增生过程 ,与 PF的发生发展有密切的关系。

Objective To investigate the role of ET from experimental pulmonary fibrosis in rats.Method The rats received blemony and received normal saline respectively. The plasma and bronchoalveolar lavage fluid (BALF) of the rats in test group (BLM) and control group (normal saline) were measured for their ET levels by radioimmunoassay and the lung tissue was observed for the ET expression by immunohistochemical staining on the lst, 3rd, 7th, 14th and 28th of the experiment. Results (1) The ET levels in plasma and BALF in the test group during the early phase of the experiment were significantly increased compared with control group. (2) The ET expression increased in airway epithelium and inflammatary cells in the test group. (3) ET level was correlated with polymo phornuclear leukocytes and lymphocytes in BALF. There was no corretation between BALF-ET value and total cell count. Conclusion The levels of ET in BALF may be responsible for both degree of alveolitis and fibrogenic acivith, and may be a potential marker for early diagnosis of the disease. ET-1 is involved in both exudative and proliferative phases and contribute to the genesis and progresson of pulmonary fibrosis.