Objective: To investigate the effects of hypoxia on the expression of PKC mRNA in pulmonary artery smooth muscle cells (PASMC) and endothelial cells.
Methods: In situ hybridization technique was used to detect the expression of PKC mRNA in different segments of pulmonary artery smooth muscle and endothelial cell (EC) in rats, and the effect of hypoxia on the expression of PKC alpha mRNA in pulmonary artery smooth muscle and endothelial cells in vivo and in vitro.
Results: PKC alpha mRNA was expressed in normal PASMC and EC in rats. The expression of PKC alpha mRNA was higher in the PASMC of intra-acinar pulmonary arteriole than that of muscular arteriole (P < 0.01). In 14 and 28 days of hypoxia, the expression of PKC alpha mRNA was higher both in EC of intraacinar pulmonary arteriole and muscular arteriole and PASMC of intra-acinar pulmonary arteriole (P < 0.01). After 14 days of hypoxia, the expression of PKC alpha mRNA was not significantly changed. But by 28 days, it became significantly higher (P < 0.01). PKC alpha mRNA was expressed in normal PASMC and EC in pigs in vitro. After 1 h of hypoxia, no change was detected, but PKC alpha mRNA expression was significantly higher after 48 h and 72 h of hypoxia in PASMC and EC in vitro (P < 0.01).
Conclusions: Hypoxia can promote expression of PKC alpha m RNA in PASMC and EC, especially in the PASMC of intra-acinar pulmonary arterioles. PKC alpha may play an important role in the development of hypoxia pulmonary hypertension.