AIMTo study the effect of Safflower injection (a compound of Chinese Traditional medicine) on pulmonary hypertension in rat during chronic hypoxia and hypercapnia.

METHODSSprague-Dawley rats were randomly divided into normal control group (A), hypoxic hypercapnic group (B), hypoxic hypercapnia + Safflower injection group (C). The concentration of TXB2 and 6-keto-PGF18 in plasma and in lung homogenate were detected by the radioimmunoassay.

RESULTS(1) mPAP, weight ratio of right ventricle (RV) to left ventricle plus septum (LV + S) were much higher in rats of hypoxic hypercapnic group than those of control group. Differences of mCAP among the three groups were not significant. (2) The concentration of TXB2 and the ratio of TXB2/6-keto-PGF1a were significantly higher in rats of B group than those of A and C group. (3) The results examined by light microscopy showed that WA/TA (vessel wall area/total area), SMC (the density of medial smooth muscle cell) and PAMT (the thickness of medial smooth cell layer) were significantly higher in rats of B group than those of A and C group. (4) The results examined by electron microscopy showed proliferation of medial smooth muscle cells and collagen fibers of pulmonary arterioles in rats of B group, and Safflower injection could reverse the changes mentioned above.

CONCLUSIONSafflower injection may inhibit hypoxic hypercapnia pulmonary hypertension and pulmonary vessel remodeling by decreasing the ratio of TXB2/6-keto-PGF1a.