[The effect of hypoxic endothelial cells conditioned medium on the growth of pulmonary artery smooth muscle cells].

The effect of hypoxic endothelial cells conditioned medium (HECCM) on porcine pulmonary artery smooth muscle cells (PASMC) were studied with phase contrast microscopy, 3H-thymidine labelling technique and flow cytometric analysis. The results showed that HECCM could stimulate PASMC proliferation, by promoting the cells from G0/G1 phase into S phase, and increased 3H-thymidine incorporation. Direct hypoxic condition could inhibit cultured PASMC proliferation, and arrested them at the G0/G1 phase, accompanied with decrease of 3H-thymidine incorporation. Statistical significance was obtained between data of these two groups respectively (P < 0.01). It is believed that PAEC may be the target cell to hypoxic injury, and hypoxia may lead PAEC to secrete some growth factors in auto-or paracrine manner which is effective in promoting PASMC proliferation.