低氧对肺动脉内皮细胞PDGF—B链释放及平滑肌细胞生长的影响

应用蛋白ｄｏｔｂｌｏｔ技术检测了低氧内皮细胞条件培养液（ＨＥＣＣＭ）和常氧内皮细胞条件培养液（ＮＥＣＣＭ）内ＰＤＧＦ相对含量，并利用［３Ｈ］－ＴｄＲ掺入法和流式细胞术观察了ＨＥＣＣＭ和ＮＥＣＣＭ及加入特异ＰＤＧＦ抗体对肺动脉平滑肌细胞（ＰＡＳＭＣ）生长的影响。结果表明，ＨＥＣＣＭ中的ＰＤＧＦ含量明显高于ＮＥＣＣＭ；ＨＥＣＣＭ能明显增强ＰＡＳＭＣ内ＤＮＡ合成，促进ＰＡＳＭＣ从Ｇｏ／Ｇ１期进入Ｓ期；当预先加入ＰＤＧＦ－Ｂ链抗体时，则会明显地抑制ＨＥＣＣＭ对ＰＡＳＭＣ的ＤＮＡ合成，阻止ＰＡＳＭＣ从Ｇｏ／Ｇ１期进入Ｓ期。结果提示，低氧时ＰＡＳＭＣ增殖与肺动脉内皮细胞分泌释放ＰＤＧＦ增加有关

EFFECTS OF HYPOXIA ON THE RELEASE OF PDGF B CHAIN FROM PULMONARY ARTERY ENDOTHELIAL CELLS AND ON GROWTH OF PULMONARY ARTERY SMOOTH MUSCLE CELLS

Platelet derived growth factor (PDGF), content in hypoxic endothelial cells conditioned medium (HECCM) and normoxic endothelial cells conditioned medium (NECM) was determined using protein dot blot assay. The effects of HECCM and NECCM on the growth of pulmonary artery smooth muscle cells (PASMC) were assessed with thymidine incorporation technique and flow cytometric analysis. PDGF content in HECCM was higher than that in NECCM. HECCM dramatically enhanced the DNA synthesis in PASMC and significantly promoted the cell cycle progression of PASMC from G 0/G 1 phase to S phase. In addition, administration of anti PDGF B chain monoclonal antibodies blocked markedly the DNA synthesis of PASMC stimulated by HECCM and obviously inhibited the entry of the cells from G 0/G 1 phase into S phase. These results suggest that increased PDGF release from pulmonary artery endothelial cells under hypoxia could stimulate the proliferation of PASMC which may induce pulmonary vascular reconstruction and involve in the development of hypoxic pulmonary hypertension.