肾上腺髓质素原N端20肽对血管紧张素刺激心肌成纤维细胞生成NO的影响

Effects of proadrenomedullin N-terminal 20 peptide on angiotensin II-induced NO production in rat cardiac fibroblasts

目的探讨肾上腺髓质素原N端20肽(PAMP)对血管紧张素II刺激心肌成纤维细胞(CFs)生成NO的影响及意义。方法采用胰酶消化、差速贴壁法培养新生SD大鼠CFs,以硝酸还原法测定细胞培养液中NO的浓度,分别观察不同浓度AngII、PAMP、及AngII+PAMP对CFs生成NO的影响。结果(1)10-9、10-8、10-7、10-6μmol/LAngII组细胞培养液中的浓度是:(73.88±2.23)、(64.34±3.02)、(54.12±2.82)、(40.21±1.45)μmol/L,各组之间有显著性差异(P<0.01)。(2)10-9、10-8、10-7、10-6μmol/LPAMP组细胞培养液中NO的浓度分别为(74.40±3.42)、(74.91±2.66)、(75.77±3.31)、(74.23±2.43)μmol/L,而空白组为(74.57±2.49)μmol/L。各组之间无显著性差异(P>0.05)。(3)10-7μmol/LAngII+(10-9、10-8、10-7、10-6μmol/L)PAMP组培养液中NO合成浓度分别为(66.15±2.95)、(80.58±3.77)、(88.67±1.46)、(96.22±2.96)μmol/L,各组间有显著性差异(P<0.01)。结论随AngⅡ浓度增加可显著抑制CFs分泌NO,而PAMP对CFS合成NO无明显影响,但PAMP与AngII共同培养时,随PMAP浓度增加,NO的合成呈依从性增多。

Objective To explore the effects of proadrenomeduUin N-terminal 20 peptide （PAMP） on nitric oxide （NO） production in rat cardiac fibroblasts （CFs） induced by angiotensin Ⅱ （AngⅡ） stimulation. Methods Neonatal SD rat CFs isolated by trypsin digestion were cultured and stimulated with PAMP, AngⅡ or their combination, and NO production in the CFs in response to the treatments was measured by nitric acid reductase method. Results NO levels in the cell culture treated with 1×10^9, 1×10^-8, 1×10^-7, and 1×10^-6 μmol/L AngⅡ were 73.88±2.23, 64.34±3.02, 54.12±2.82, and 40.21±1.45 μmol/L, respectively, showing significant differences between the groups （P〈0.01）, whereas treatment of the cells with 1×10^-9, 1×10^8, 1×10^-7, and 1×10^-6 μmol/L PAMP did not result in significant variation in NO production （74.40±3.42, 74.91 ±2.66, 75.77± 3.31, and 74.23±2.43 μmol/L, respectively） in comparison with that of the blank control group （74.57±2.49 μmol/L, P〉0.05）. Combined treatments with 1×10^-7 μmol/L AngⅡ and PAMP at 1×10^-9, 1×10^-8, 1×10^-7, and 1×10^-6 μmol/L PAMP caused significant increment of NO production （66.15±2.95, 80.58±3.77, 88.67± 1.46, and 96.22±2.96 μmol/L, respectively, P〈0.01） in a PAMP dose-dependent manner, suggesting the abolishment of AngⅡ-induced enhancement of NO production in the CFs by PAMP. Conclusion PAMP increases NO production in the CFs in the presence of AngⅡ but it does not induce significant changes in NO production when used alone.