目的 :观察肺癌、慢性阻塞性肺疾病、慢性肺心病及正常人血管紧张素转换酶基因多态性 (ACEGP)的变化及其与血清血管紧张素转换酶 (sACE)水平的关系.方法 :ACEGP测定采用PCR ,sACE采用紫外分光光度法测定.结果 :正常人和肺心病组Ⅰ型基因占优势 (分别为 5 7.9%和 6 0 .7%) ,而肺癌组和慢喘支组D型占优势 (分别为 6 1.8%和 5 9.5%).肺癌组I/D和I等位基因频率均明显低于正常组 (P“,”Objective: To investigate changes in angiotensin converting enzyme gene polymorphism (ACEGP) and serum angiotensin converting enzyme (sACE) in patients with lung cancer, chronic asthmatic bronchitis and cor pulmonale. Methods: ACEGP was measured by PCR, while sACE was measured with ultraviolet spectrophotometry. PCR primers were flanking the polymorphic region in intron 16 of the ACE gene. Results: I ACE genotype was dominated by normal control and cor pulmponale ( accounting for 57.9% and 60.7% respectively), but D ACE genotype was dominated by lung cancer and chronic asthmatic bronchitis (61.8% and 59.5% respectively). The percentages of I/D and I allele were both lower than those in normal control , but the ratio of I allele was obviously higher in chronic asthmatic bronchitis (40.5%) than that in normal control (57.9%), though there were no obviously different indices between chronic asthmatic bronchitis and lung cancer. The percentage of I allele was significantly higher in cor pulmonale (60.7%) than that in lung cancer (38.2%). Changes in sACE were not the same as that of the genotype. There was a lower level of sACE in cor pulmonate but there were no differences among lung cancer, chronic asthmatic bronchitis and normal control groups. In normal control and other three groups, the levels of sACE were higher in D/D genotype than that in I/I, obvious differences were seen in normal control and cor pulmonale groups. Conclusion: These results suggested that there was a close relationship between ACEGP and certain lung diseases, such as lung cancer and chronic asthmatic bronchitis. Changes in sACE were related to ACEGP and other factors.