Effects of 3,4-dihydroxyacetophenone on cytosolic calcium in pulmonary artery endothelial and smooth muscle cells during acute hypoxia.

The effects of 3, 4-Dihydroxyacetophenone (3, 4-DHAP) on cytosolic free calcium [Ca2+]i in pulmonary artery endothelia (PAECs) and smooth muscle cells (PASMCs) during acute hypoxia were studied. Porcine pulmonary artery endothelial and smooth muscle cells (PASMCs) were cultured primarily, and they were divided into 4 groups: groups incubated under normoxia or hypoxia and those with or without treatment with 3,4-DHAP. The [Ca2+]i of both PAECs and PASMCs was measured by determining the fluorescence of fura 2 AM on spetrofluorometer. Our results showed that hypoxia caused significant elevation of [Ca2+]i, in both PAECs and PASMCs, 3,4-DHAP could attenuate the hypoxic elevation of [Ca2+]i only in PASMCs but not in PAECs. It is concluded that 3,4-DHAP decreases the hypoxic elevation of [Ca2+]i in PASMCs. This might contribute to its inhibitory effect on hypoxic pulmonary vasoconstriction.