Effect of safflower injection on expression of COX-2 mRNA and protein in chronic hypoxic hypercapnic rat pulmonary arterioles / 中国病理生理杂志

ABSTRACT

AIM: To study the effect of safflower injection on expression of COX-2 mRNA in chronic hypoxic hypercapnic rat pulmonary arterioles.METHODS: Sprague-Dawley rats were randomly divided into normal control group,hypoxic hypercapnic group(B),hypoxic hypercapnia+ safflower injection group(C).The concentration of TXB2 and 6-Keto-PGF1? in plasma and in lung were detected by the technique of radioimmunoassay.COX-2 mRNA was observed in arterioles from rats by the technique of in situ hybridization.RESULTS: ① Mean pulmonary arterial pressure(mPAP),weight ratio of right ventricle(RV) to left ventricle plus septum(LV+S) were much higher in B group than those in control group.No significant difference of mean carotid arterial pressure(mCAP) was observed in three groups.② The concentration of TXB2 and the ratio of TXB2/6-keto-PGF1? were significantly higher in B group than those in control group.③ Light microscopy showed that vessel wall area/total area,the density of medial smooth muscle cells and the thickness of medial smooth cell layer were significantly higher in B group than those in control group.Electron microscopy showed proliferation of medial smooth muscle cells and collagenous fibers in pulmonary arterioles in B group.Safflower injection reversed the changes mentioned above.④ Expression of COX-2 mRNA in pulmonary arterioles was much higher in C group than those in B group.Differences of COX-1 mRNA in pulmonary arterioles were not significant between these two groups.CONCLUSION: Safflower injection increases the expression of COX-2 mRNA in chronic hypoxic hypercapnic rat pulmonary arterioles,indicating an important mechanism that safflower injection inhibits the formation of hypoxic hypercapnia pulmonary hypertension and pulmonary vessel remodeling.