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 ...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.展开更多
文摘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.
