[Effect and mechanism of chimonin on pulmonary hypertention of chronic hypoxia and hypercapnic rats].

AIM: To study the effect of chimonin on chronic hypoxia and hypercapnic pulmonary hypertension and to explore its mechanism.

METHODS: SD rats were randomly divided into normal control group (A), hypoxic hypercapnic group(B), hypoxic hypercapnia + chimonin group (C). HO-1 and HO-1 mRNA was observed in pulmonary arterioles of rats by the technique of immunohistochemistry and in situ hybridization.

RESULTS: (1) mPAP was significantly higher in rats of B group than that of A and C group. Differences of mCAP were not significant in three groups. (2) Blood CO concentration was significantly higher in rats of B group than that of A group, it was significantly higher in rats of C group than that of B group. (3) 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) Electron microscopy showed proliferation of medial smooth muscle cells and collagenous fibers of pulmonary arterioles in rats of B group, and chimonin could reverse the changes mentioned above. (5) HO-1 and HO-1 mRNA in pulmonary arterioles was significantly higher in rats of B group than that of A group, they were significantly higher in rats of C group than that of B group.

CONCLUSION: Chimonin can inhibit hypoxic hypercapnia pulmonary hypertension and pulmonary vessel remodeling by further increasing the expression of HO-1 mRNA.