Expression of 15-lipoxygenases in pulmonary arteries after hypoxia

SummaryAims: We have previously reported that subacute hypoxia upregulates and activates the steady state expression of pulmonary artery 15-lipoxygenase (15-LOX). However, there are two 15-LOX isoenzymes, 15-LOX-1 and 15-LOX-2, which are expressed in pulmonary arteries that have not been previously studied. In the present study, we identified the differential expression of the two isoenzymes in normoxic or hypoxic intrapulmonary arteries of rats, pulmonary artery endothelial cells (PAECs) and pulmonary artery smooth muscle cells (PASMCs) from the main branches of pulmonary artery of neonatal bovines.Methods: Immunohistochemistry, in situ hybridisation, RT-PCR, and Western blotting were employed to identify the differential expression of the two isoenzymes.Results: 15-LOX-1 was expressed in both normoxic and hypoxic rat arteries. In contrast, 15-LOX-2 was hardly detectable in normoxic vessels by immunohistochemistry and Western blotting, but it was detected in hypoxic arteries. In cultured bovine pulmonary...