Objective: To study the effects of hypoxia, directly or mediated by pulmonary arterial endothelial cells, on energy metabolism, cell cycle, platelet derived growth factor (PDGF) and PDGF receptor mRNA expression of vascular pericytes of the lung in vitro.
Methods: Use of MTT colorimetric assay, flow cytometry, nucleic acid in situ hybridization and automatic image analysis for quantitative analysis.
Results: Hypoxia promoted vascular pericyte proliferation directly or through the mediation of endothelial cells to promote vascular pericyte proliferation from static phase (G(0), G(1) phase) to DNA synthesis phase (S phase) and mitotic phase (G(2) + M phase) and upregulate gene expression of PDGF and PDGF-R by vascular pericyte of the lung.
Conclusions: The low oxygen tension of alveolar gas and hypoxemia may promote transcription of PDGF and its receptor gene. Paracrine and autocrine PDGF may induce proliferation of vascular pericytes of the pulmonary vessels and may play a role in pulmonary hypertension and structural remodeling of the pulmonary vessels, especially in the neomuscularization of nonmuscular pulmonary arterioles.