Roles of NHE-1 in the proliferation and apoptosis of pulmonary artery smooth muscle cells in rats
Yao, W.; Qian, G.; Yang, X.
Chinese Medical Journal 115(1): 107-109
2002
ISSN/ISBN: 0366-6999 PMID: 11930639 Document Number: 548692
Objective: To evaluate the roles of Na+/H+ exchanger-1 (NHE-1) in the proliferation and apoptosis of pulmonary artery smooth muscle cells in rats. Methods: Twenty Wistar rats were randomized into control group and 3-week hypoxic group. Intracellular pH (pHi) of the smooth muscle was determined with fluorescence measurement of the pH-sensitive dye BCECF-AM, and the expression of NHE-1 mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR). Primary culture of pulmonary artery smooth muscle cells in vitro was performed. In situ cell death detection kit (TUNEL) was used for studying the effect of specific NHE-1 inhibitor-dimethyl amiloride (DMA) on the apoptosis of muscle cells which had intracellular acidification. Results: pHi value and NHE-1 mRNA expression of pulmonary artery smooth muscle cells were significantly higher in the hypoxic group than in the control group (P<0.01, P<0.001). DMA elevated the apoptotic ratio remarkably. The effect was enhanced when DMA concentration increased and the time prolonged. Conclusions: With the function of adjusting pHi, NHE-1 may play an important role in the proliferation and apoptosis of pulmonary artery smooth muscle cells.