血管钠肽抑制低氧对大鼠心成纤维细胞内钙浓度升高的作用

Vasonatrin peptide attenuates hypoxia-induced increase in [Ca^(2+) ]_i of culured rat cardiac fibroblasts

为了观察血管钠肽 (vasonatrinpeptide ,VNP)对低氧作用时心成纤维细胞增殖的影响 ,将分离纯化乳鼠心成纤维细胞 ,随机分为 4组 :对照组、低氧组 ( 2 %～ 3 % )、VNP组 ( 10 -8～ 10 -6 mol/L)和VNP +低氧组。用MTT比色法、3H TdR掺入法观察细胞增殖情况 ,采用激光共聚焦方法研究VNP对细胞内钙浓度 ( [Ca2 +]i)水平的影响。旨在探讨VNP对低氧刺激心成纤维细胞增殖的影响及机制。我们发现 ,低氧可以使培养的乳鼠心成纤维细胞MTT光吸收值 (OD值 )较对照组显著增高 (P <0 0 5 )。VNP ( 10 -6 mol/L)可以显著降低低氧刺激的心成纤维细胞MTTOD值和细胞内 3H TdR掺入量的增高 (P <0 0 5 )。对照组 [Ca2 +]i 水平无显著差异 ,低氧组 [Ca2 +]i 水平显著升高 ,而VNP ( 10 -6 mol/L)能使升高的 [Ca2 +]i 水平较对照组、低氧组显著降低 (P <0 0 5 )。结果表明 ,VNP能减弱低氧对心成纤维细胞生长的刺激作用 ,其机制可能与Ca2 +等信号转导分子有关。

The purpose of this work was to test the hypothesis that vasonatrin peptide (VNP) can attenuate the growth promoting effect by hypoxia in cardiac fibroblasts of cultured neonatal rats. Cultured fibroblasts were divided into four groups: control group, hypoxia group, VNP group and VNP+hypoxia group. The growth of cardiac fibroblasts was observed using MTT method and the incorporation of ~ 3H TdR, and the effect of VNP on the intracellular level of Ca 2+ was measured by means of interactive laser cytometry. It was found that hypoxia (2%～3%) increased significantly the MTT optical density (OD) of cardiac fibroblasts ( P <0 05 vs control group), but the increase was greatly attenuated in the VNP (10 -6 mol/L) group and also the incorporation of ~ 3H TdR in cardiac fibroblasts ( P <0 05 vs hypoxia group). VNP (10 -6 mol/L) also decreased the intracellular level of Ca 2+ which was increased by hypoxia ( P <0 05) as compared with control and hypoxia group. These findings demonstrate that VNP can attenuate the hypoxia induced growth promoting effect in cardiac fibroblasts, which may be associated with the elevation of intracellular Ca 2+ .