慢性低氧对大鼠肺组织电压门控钾通道表达的影响

Effect of chronic hypoxia on the gene expression of voltage-gated potassium channels in pulmonary tissue of rats

目的 :探讨慢性低氧对大鼠肺组织电压门控钾通道亚型Kv1 5、Kv2 1、Kv9 3表达的影响。方法 :将12只Wistar大鼠随机分为对照组和慢性低氧组 ,每组 6只。采用RT -PCR和Westernblot对大鼠肺组织匀浆中Kv1 5、Kv2 1、Kv9 3mRNA和Kv1 5蛋白质的表达进行观察。结果 :慢性低氧组大鼠肺组织匀浆中Kv1 5、Kv2 1、Kv9 3mRNA和Kv1 5蛋白质表达明显低于对照组 (P <0 0 1)。结论 :慢性低氧可以从转录、翻译两个水平抑制大鼠肺组织中Kv1 5、Kv2 1Kv9 3的表达 ,Kv1 5、Kv2 1、Kv9 3表达的减少必将导致Kv数目的减少和电流的降低。Kv1 5、Kv2 1、Kv9

AIM: To investigate the effect of chronic hypoxia on the expression of voltage-gated potassium channels α subunits in pulmonary tissue. METHODS: Twelve Wistar rats matched with age and body weight were randomly divided into control and chronic hypoxic groups. The expression of mRNA and protein of Kv1.5, Kv2.1, Kv9.3 in pulmonary tissues were detected with reverse transcription-PCR (RT-PCR) and Western Blot. RESULTS: The expression of Kv1.5, Kv2.1 and Kv9.3 gene were found in pulmonary tissue of rats exposed either to normoxia or chronic hypoxia. Chronic hypoxia decreased mRNA expression of Kv channel subunit (Kv1.5, Kv2.1, Kv9.3) in pulmonary tissue from 0.473±0.022, 0.912±0.084, and 0.319±0.019 to 0.256±0.008, 0.406±0.031 and 0.114±0.009, respectively (P<0.01, n=6). Consistently, chronic hypoxia attenuated protein expression of Kv1.5 from 0.952±0.127 to 0.456±0.089 (P<0.01, n=6). CONCLUSIONS: The diminished transcription and expression of Kv α subunits might reduce the number of Kv channels and decrease Kv current. Kv1.5, Kv2.1 and Kv9.3 might be oxygen sensitive genes. The hypoxia-mediated transcriptional regulation of Kv channel genes in pulmonary artery smooth muscle cells might play a role in the development of hypoxic pulmonary vasoconstriction and pulmonary hypertension during chronic hypoxia. [