自发性高血压大鼠中血小板源生长因子—AA及其受体表达与血管平滑机细胞增殖的关系

为明确血小板源生长因子 AA(plateletderivedgrowthfactor AA ,PDGF AA)及PDGF α受体在自发性高血压大鼠 (spontaneouslyhypertensionrats,SHR)血管平滑肌细胞 (vascularsmoothmusclecells,VSMCs)增殖中的作用 ,采用Westernblot、3 H]TdR及 3 H]Leu掺入率等方法 ,观察在SHR和WKY大鼠VSMC中PDGF AA及PDGF受体表达的差异 ;在PDGF AA刺激下VSMC增殖和肥大反应的变化。结果显示 ,SHR VSMC中PDGF AA、PDGF α受体蛋白表达明显高于WKY VSMC(P <0 0 1) ,而PDGF β受体蛋白表达在SHR VSMC与WKY VSMC无明显差异 ;在不同浓度PDGF AA刺激下 ,增殖细胞核抗原 (PCNA)及3 H掺入率在SHR VSMC明显增强且呈剂量依赖性增加 (P <0 0 1)。本研究表明PDGF A链及其α受体的自泌性增高 ,可能是导致SHR VSMC异常增殖和肥大 ,并导致血管构型变化的重要原因之一

Relationship between proliferation of vascular smooth muscle cells and PDGF-AA and PDGFR-alpha expression in SHRs

To explore the role of platelet derived growth factor-AA (PDGF-AA) and PDGFR-alpha expression in the proliferation and hypertrophy of vascular smooth muscle cells (VSMCs) in spontaneously hypertension rats (SHR), protein expression of PDGF-AA, PDGFR-alpha and PDGFR-beta in SHR/Wistar-Kyoto (WKY)-VSMC was observed by Western blot. Proliferation and hypertrophy of SHR-VSMCs induced by PDGF-AA were observed by measurement of PCNA and (3)H] incorporation. PDGF-AA and PDGFR-alpha expression was markedly increased in SHR-VSMCs compared with that in WKY-VSMCs, but PDGFR-beta was not different in SHR and WKY-VSMCs. PDGF-AA induced PCNA expression and (3)H] incorporation was increased in a dose-dependent manner in SHR, but not in WKY. It is suggested that an enhancement of PDGF-AA and PDGFR-alpha in SHRs may be one of the important factors for vascular modeling.