[The change of nuclear factor-kappa B expression in the lung tissues of chronic hypoxic rats]

To investigate the change of nuclear factor-kappa B (NF-kappaB) expression in the lung tissues from chronic hypoxic rats and the role of NF-kappaB in the pathogenesis of hypoxic pulmonary hypertension.

Twenty male SD rats were randomly divided into two groups: control group and hypoxic group. The animal model of pulmonary hypertension was established by exposing the rats to normabaric hypoxic conditions for three weeks. The mean pulmonary arterial pressure (mPAP) was measured by a right cardiac catheterization. The indices of wall thickness of pulmonary arteriole (WT% and WA%) were measured by a computerized image analyzer. NF-kappaB expression in lung tissues were observed by using immunohistochemistry.

(1) The mPAP of hypoxic rats was (29.1 +/- 4.5) mmHg,and it was (16.8 +/- 2.6) mmHg in normal rats, there was significant difference between two groups (P < 0.001). (2) In hypoxic group, the WT% was (22.36 +/- 2.99)% and WA% was (69.14 +/- 5.38)%; in normal group, WT% was (15.36 +/- 3.08)% and WA% was (46.75 +/- 6.54)%, the differences were significant (P < 0.01). (3) Both normal and hypoxic group, there were positive cells for NF-kappaB nuclear staining in lung tissues of rats. The percentage of positive cells for NF-kappaB nuclear staining in bronchiolar epithelial cells was significantly increased in the hypoxic group [(29.11 +/- 1.12)%] than that in the control group [(12.23 +/- 1.08)%], P < 0.001.

NF-kappaB expression is increased in the lung tissue of rats with chronic hypoxia. It may play a role in the pathogenic process of hypoxic pulmonary hypertension.