醛固酮降低新生大鼠心肌成纤维细胞iNOS表达和NO含量

Aldosterone decreases iNOS expression and NO level in cardiac fibroblases of neonatal rat

目的为探讨醛固酮诱导心肌成纤维细胞(CFs)增殖及其对诱导型一氧化氮合酶 一氧化氮(iNOS NO)系统活性的影响。方法用胰酶消化法分离、培养新生SD大鼠CFs,采用MTT比色法、硝酸还原酶法、分光光度法和半定量RT PCR技术,观察不同浓度醛固酮对CFs的增殖、NO含量、iNOS活性和iNOSmRNA表达的影响。结果醛固酮(10 -11～10 -7mol/L)能剂量依赖性促进CFs的增殖,降低CFs的NO含量、iNOS活性及iNOSmRNA的表达(均P <0 .0 5 ) ,且螺内酯能逆转醛固酮的上述作用。醛固酮干预下CFs增殖数目与NO含量和iNOS活性呈显著负相关(r分别为- 0 . 94 2、- 0 . 978,均P <0 . 0 1)。结论醛固酮能剂量依赖性降低CFs的iNOS -NO系统活性,促进CFs增殖;螺内酯能逆转此作用。

Objective To investigate the changes of inducible nitric oxide synthase (iNOS) activity in neonatal rat cardiac fibroblasts(CFs) induced by aldosterone. Methods CFs were isolated by trypsin digestion, MTT colorimetric assay was adopted to evaluate cell proliferation, Nitric acid reductase method, spectrophotometry and reverse transcription-polymerase chain reaction were used to detect the NO 2-/ NO 3- contents, iNOS activity and iNOS mRNA expression respectively at different dose with aldosterone. Results Aldosterone (10 -11～10 -7mol/L) increased CFs proliferation and decreased NO 2-/ NO 3- contents, iNOS activity and iNOS mRNA expression in a dose-depend manner(P<0.05), the effects of aldosterone were reversed by spironolactone. CFs proliferation was negatively correlated with NO 2-/ NO 3- contents and iNOS activity induced by different concentrations of aldosterone (r =-0.942?-0.978,P<0.01). Conclusion Aldosterone decreases iNOS-NO system activity in neonatal rat CFs, and stimulates proliferation of CFs. The effects of aldosterone on CFs can be reversed by spironolactone.