[Effects of hypoxia on the expression of platelet-derived growth factor (PDGF) gene and PDGF-B chain protein in porcine pulmonary artery endothelial cells].

Northern blot, slot blot hybridization and quantitative immunocytochemistry analyses were used to study the effects of hypoxia on the expression of PDGF gene and PDGF-B chain protein in cultured pulmonary artery endothelial cells (PAEC). Hypoxia (3% oxygen) significantly increased PDGF-B chain mRNA in PAEC, whereas mRNA level of PDGF-A chain was not increased significantly in comparison with normoxic control (21% oxygen). PDGF-B chain immunoreactivity on PAEC exposed to hypoxia was markedly stronger than that of normoxic PAEC and PDGF-B China immunoreaction. was found in cytoplasm and perinuclear region of the hypoxic PAEC, however, only in the nuclear region of normoxic PAEC. Increased expression of PDGF-B chain protein roughly paralleling that of PDGF-B mRNA was also observed. These results suggest that hypoxia may stimulate the expression of PDGF-B chain by PAEC in vivo and PDGF may play an important role in the vascular remodeling of hypoxic pulmonary hypertension.