Chronic hypoxia (CH) causes pulmonary hypertension (PH) with vascular remodeling, increase in vascular tone and altered reactivity to agonists.These changes involve alterations in multiple Ca2+ pathways in pulmonary arterial smooth muscle cells (PASMCs).Here we found that the mechanosensitive TRPV4 channel was upregulated in pulmonary arteries (PAs) of CH rats.