The time-course of mRNA and protein expression of inducible nitric oxide synthase in pulmonary artery and thoracic aorta induced by endotoxemia in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the time-course of mRNA and protein expression of inducible nitric oxide synthase (iNOS) in pulmonary artery and thoracic aorta and the difference in mRNA and protein expressions of iNOS between pulmonary artery and thoracic aorta induced by endotoxemia in rats. Methods Forty-eight Wistar rats of both sexes weighing 350-450g were randomly divided into 2 groups control group in which animals received normal saline intraperitoneally (ip) and were killed 3h later by dislocation of cervical vertebrae (n=12); test groups in which animals were injected intraperitoneally lipopolysaccharide (LP) 4mg-kg-1 in 2ml of normal saline and were killed after 3h ( n = 12), 8h ( n = 12) , and 48h( n = 12) . Chest was opened immediately and pulmonary artery (PA) and descending thoracic aorta ( TA) were removed. mRNA and protein expression of iNOS in PA and TA were measured by RT-PCR and Western blot.Results The mRNA and protein expressions of iNOS in PA peaked at 8h and that in TA at 3h after ip LPS injection. The levels of mRNA and protein expressions of iNOS in both PA and TA returned to control level at 48h after ip LPS injection. The levels of mRNA and protein expressions of iNOS in PA at 3h and 8h after ip LPS injection were significantly higher than those in TA.Conclusion The mRNA and protein expressions of iNOS in PA and TA after LPS injection are time-dependent. The mRNA and protein expressions of iNOS in TA after LPS injection are earlier than those in PA but the level of mRNA and protein expressions of iNOS in PA after LPS injection is higher than that in TA.