Abstract: Abstract:Objective To investigate the significance of peroxisome proliferator-activated receptor (PPAR)γ expression in the lung tissue of rats with chronic hypoxic pulmonary hypertension (HPAH). Methods Forty male Sprague-Dawley rats were randomly divided into four groups (n=10 for each group): normal control group (NC), hypoxia control group-one-week (HC-1w), hypoxia control group-two-week (HC-2w) and hypoxia control group-three-week (HC-3w). Normal control group was raised under normal oxygen condition in ventilated animal cage for three weeks. The other HC groups were placed in a low oxygen chamber (O2 concentration of 10%) from 9： 00 AM-5:00 PM (8 h/d) everyday by one week, two weeks and three weeks. The mean pulmonary arterial pressure (mPAP), right ventricular systolic pressure (RVSP) were detected. The index of right ventricular hypertrophy RV/(LV+S) was measured by dissecting rat heart. The morphological changes of the small pul⁃ monary arteries were observed by HE staining, and the percentage of vascular wall thickness (WT%) was calculated. The ex⁃ pression level of PPARγ protein was detected by Westren blot assay. Results The mPAP, RVSP and RV/(LV+S) were sig⁃ nificantly higher in HC groups than those of NC group (P<0.05). The morphology of pulmonary arteries showed vessel wall thickening and vessel lumina stenosis in HC groups compared with that of NC group. The PPARγ expression in lung tissue was significantly lower in HC groups than that of NC group, and the downward trend was more obvious with the extension of time. Conclusion PPARγ plays an important role in the occurrence and development of chronic hypoxic pulmonary hyper⁃ tension.

Key words: hypertension, pulmonary, anoxia, PPAR gamma, rats, Sprague-Dawley, hypoxic pulmonary artery hyper? tension