The Science Journal of the American Association for Respiratory Care

2001 OPEN FORUM Abstracts

Relationship between expression of heme oxygenase-1 mRNA and

pulmonary hypertension induced by hypoxic hypercapnia

WANG Liangxing, HUANG Xiaoying,CHEN Shaoxian, XU Zhengjie, WANG Qunji, FAN Xiaofang Respirology Department,first afficiated hospital, Wenzhou Medical College,Wenzhou 325003,China)

AIM: To study the effectof chronic hypoxic hypercapnia on expression of heme oxygenase-1(HO-1).

Methods: Thirty-six Sprague-Dawleyrats were randomly divided into three groups:normal control group(A),hypoxichypercapnic group(B), hypoxic hypercapnia+hemin group(C). HO-1 was observedin arterioles from rats by the technique of immunohistochemistry,HO-1 mRNA wasobserved in arterioles from rats by the technique of in situ hybridization.Theaverage value of integral light density(LD) of HO-1 and HO-1 mRNA in pulmonaryarterioles were detected by an image analysor and the relative content of HO-1and HO-1 mRNA were calculated.

Results: mPAP and weight ratioof right ventricle(RV) to left ventricle plus septum(LV+S) were significantlyhigher in rats of B group than those of A group(p<0.01) and they were muchlower in rats of C group than those of B group(p<0.01).Differences of mCAPwere not significant in three groups(p>0.05); Blood CO concentration wassignificantly higher in rats of B group than that of A group(p<0.01), bloodCO concentration was significantly higher in rats of C group than that of Bgroup(p<0.01); Light microscopy showed that WA/TA(vessel well area/totalarea) SMC (the density of medial smooth muscle cell) and PAMT(the thicknessof medial smooth cell layer) were significantly higher in rats of B group thanthose of A group(p<0.01),WA/TA SMC and PAMT were significantly lower in ratsof C group than those of B group(p<0.01); Electron microscopy showed proliferationof medial smooth muscle cells and collageous fibers of pulmonary arteriolesin rats of B group, and hemin could reverse the changes mentioned above; Immunohistochemstryshowed that LD of HO-1 in pulmonary arterioles was significantly higher in ratsof B group than that of A group(p<0.01), HO-1 in pulmonary arterioles wassignificantly lower in rats of C group than that of B group(p<0.01); Hybridizationin situ showed that LD of HO-1 mRNA in pulmonary arterioles was significantlyhigher in rats of B group than that of A group(p<0.01), HO-1 mRNA in pulmonaryarterioles was significantly lower in rats of C group than that of B group(p<0.01).

CONCLUSION: Expression ofHO-1 mRNA and HO-1 in pulmonary arterioles can be enhanced by hypoxic hypercapnia;hemin can partly inhibit pulmonary hypertension and pulmonary vessel remodelingby enhancing the Expression of HO-1 mRNA and HO-1.

[MeSH] Carbon monoxide; Hemeoxygenase; Anoxia; Hypercapnia; Hypertension,pulmonary; Gene

OF-01-109

You are here: RCJournal.com » Past OPEN FORUM Abstracts » 2001 Abstracts » Relationship between expression of heme oxygenase-1 mRNA and pulmonary hypertension induced by hypoxic hypercapni