慢性缺氧对大鼠肺内皮素表达的影响

本文以ＡＢＣ法和原位杂交技术，观察了慢性缺氧时大鼠肺组织内内皮素－１（ＥＴ－１）的表达情况，结果发现：①正常肺血管内皮细胞有少许ＥＴ－１样阳性染色物质呈现。②缺氧ＩＷ后，肺内ＥＴ－１含量增加，主要位于肺血管内皮细胞和支气管粘膜上皮细胞。③缺氧２Ｗ和３Ｗ后，ＥＴ１阳性免疫物质进一步增加，于肺泡细胞内也见到阳性染色。④缺氧１Ｗ后肺内ＥＴ－１ｍＲＮＡ表达增加，缺氧２Ｗ和３Ｗ后，ＥＴ－１ｍＲＮＡ的表达进一步加强。提示缺氧可刺激肺内ＥＴ－１ｍＲＮＡ的表达，慢性缺氧时肺内ＥＴ－１持续分泌增加，这可能是缺氧性肺动脉高压发生的重要因素之一。

THE EFFECT OF CHRONIC HYPOXIA ON THE EXPRESSION OF ENDOTHELIN-I IN RAT LUNG

In this study we investigated the localization of ET-I in the lung tissue of normoxic and hypoxic rats and the effects of chronic hypoxia on the levels of ET-I in the rats lung exposed to hypoxia (FiO_2=0. 1, 8hrs daily) for 1 week, 2 weeks and 3 weeks by means of the immunohistochemical assay and observed the ET-1 mRNA expression by the use of in situ bybridization. The results showed that: 1) There was a little ET-1 - like iminunoreactive material in the endothelial cells of the small pulmonary vessels in the control normaxic rats. 2)After exposure to hypoxia for 1 week, the ET-1 levels were increasing, mainly appeared in the pulmonary and bronchial epithelium, 3) The positive ET-1 immunoreactive materials in rat lung were further increasing in those exposed to hypoxia for 2 and 3 weeks. The ET-1immunoreactivity staining was also shown in the alveolar epithelium. 4) After exposure to hypoxia for 1 week the expression of ET-1 mRNA began to increase and after exposure for 2to 3 weeks it icreased more significantly. Our investigations indicate that chronic hypoxia may stimulate the expression of ET-1 mRNA in rat lung tissue and AT-1 may be one of the important factors causing chronic hypoxic pulmonary hypertension.