Amiloride attenuates hypoxia-induced proliferation of rats pulmonary artery smooth muscle cells by suppressing Na+/ H+ exchanger-1 / 中国应用生理学杂志

ABSTRACT

<p><b>AIM</b>To study the influence of Na+/H+ exchange inhibitor amiloride on hypoxia-induced proliferation in rats pulmonary artery smooth muscle cells (PASMCs), also observe the change of Na+/H+ exchanger-1 (NHE-1) activity and expression.</p><p><b>METHODS</b>Rats PASMGs were cultured in normoxia (21% O2) or hypoxia (2%O2) for 24 hours, as well as administered amiloride with various concentrations, cultured for 24 hours, then determined MTT OD values and rates of PCNA positive cells to investigate cells proliferation, moreover intracellular pH was determined by interactive Laser Cytometer, and Na+/H+ exchanger-1 mRNA expression was determined by RT-PCR.</p><p><b>RESULTS</b>Hypoxic exposure heightened intracellular pH and mRNA expression of NHE-1 in PASMCs, however, 3.123-50 micromol/L amiloride depressed them gradually. Additionally, hypoxic exposure raised MTT OD value and rates of PCNA positive cells, similarly, the above two indexes descended gradually with presence of 3.125-50 micromol/L amiloride.</p><p><b>CONCLUSION</b>Na+/H+ exchange inhibitor amiloride can suppress hypoxia-induced proliferation in pulmonary artery smooth muscle cells, which is due to depress activity and expression of NHE-1.</p>