Abstract: AIM: To investigate the effect of curcumin on pulmonary arterial pressure and the expression of c-Jun and c-FOS in chronic hypoxia hypercapnia rats.METHODS: SD rats were randomly divided into normal control group (NC), hypoxic hypercapnic group (HH)hypoxic hypercapnia + curcumin group (HC). c-FOS, c-Jun and their MRNA were observed in pulmonary arte-roles of rats by the technique of immunohistochemistry and in situ hybridization.RESULTS: Hemodynamics showed that MPAP was markedly lower in group HC thanthat in group HH (P < 0.01). Differences of MCAP werenot significant in three groups. Iight microscopy showed meclia thickness of pulmonary arterioles was markedly higher in group HH than that in group NC and vessecavity turned more strait in group HH than that in group NC. However, the damage of pulmonary arterioles ingroup HC was significantly slighter than that of group HH. Electron microscopy showed that structure of the en-dothelial cells in pulmonary arterioles in group HC was near to normal, and the liferation of medial smooth muscle cells and collagen fibers in adventitia is markedly lighter than those of group HH. Expression of c-Jun andC-FOS in pulmonary arterioles were significantly higher ingroup HH than NC group (P < 0. 01), and they were lower in group HC than those of group HH (P <0.01). In situ hybridization showed that c-Jun MRNA inulmonary arterioles was significantly lower in rats of group HC than that in group HH.CONCLUSION: Curcumin can inhibit hypoxic hypercapnic pulmonary hypetension and pulmonary vessel remodeling, and it may be avital mechanism of curcumin to decrease the expression ofc-Jun, c-FOS and to inhibit the proliferation of medial Smooth muscle cells.

Key words: curcumin, hypoxia, chronic, hypercap-nia, hypertension, pulmonary, activator protein-1