The injury effect of oxygen free radicals in vitro on cultured pulmonary artery endothelial cells from broilers

Pulmonary artery endothelial cells (PAEC) were isolated from broilers by the method of tissue explantation. The cells were identified using morphological features and immunocytochemical staining using a specific antiserum against factor VIII related antigen. Xanthine/Xanthine oxidase (X/XO) served as the oxygen free radical (OFR) generating system. In vitro model of oxidative injury of PAEC was established based on the X/XO system. The effect of OFR on the growth and viability of PAEC was determined with methylthiazol tetrazolium (MTT) colorimetric assay. Malondialdehyde (MDA, a product of lipid peroxidation) in culture medium of PAEC was detected by a thiobarbituric acid colorimetric assay. The results showed that PAEC survive in vitro and can be subcultured for 5-6 passages. Morphological and immunocytochemical observations of cultured cells demonstrated specific characteristics of endothelial cells. PAECs were severely damaged by OFR. The viability of cells was reduced by the X/XO system, and a dose-dependent decrease in cell viability was found with increasing XO dosages. OFR promoted lipid peroxidation of PAEC and increased the MDA concentration in culture media. These results suggest that OFR can injure the endothelial cells from broiler pulmonary arteries in vitro, which confirms previous results obtained in vivo. Oxidative injury may play an important role in the pathogenesis of pulmonary hypertension syndrome in broiler.