AIM: To clarify the role of nitric oxide (NO) system in development of chronic hypoxic hypercapnic pulmonary hepertension. METHODS: Male Sprague-Dawley rats were randomly divided into control group and hypoxic hypercapnic group. NO content of plasma was determined, constitutive nitric oxide synthase (cNOS) and inducible nitric oxide synthase (iNOS) were examined using the technique of immunohistochemistry, expression of cNOS mRNA and iNOS mRNA of arteriole were detected by in situ hybridization. RESULTS: Plasma NO concentration, cNOS activity and cNOS mRNA expression in arteriole of chronic hypoxic hypecapnic group were significantly lower than that of control group ( P

AIM: To investigate the expression of soluble guanylate cyclase protein and its mRNA in rat pulmonary artery after exposure to hypoxia and hypercapnia. METHODS: Male Sprague-Dawley rats were randomly split into 4 group, which were hypoxic hypercapnic (HH 1 week, HH 2 weeks, HH 4 weeks) group and control group, to copy pulmonary hypertensive animal model. The expression of sGC? 1 and ? 1 subunits protein of medial and small pulmonary artery was performed by immunohistochemistry with a polycolonal antibody. In situ hybridization was performed on the rat lung tissue using sGC oligonuclear probe to assay the expression of sGC? 1 subunit mRNA. RESULTS: The sGC? 1 and ? 1 subunits protein and sGC? 1 subunit mRNA were faint staining in the pulmonary small and medium artery in HH1 week, HH 2 weeks and HH 4 weeks groups compared with control group (all P

AIM: To study the effect of ligustrazine on pulmonary hypertensive rats induced by hypoxic hy- percapnia. METHODS: Thirty rats were randomly divided into three groups: control group(A), hypoxic hypercapnic group (B), hypoxic hypercapnia+ligustrazine (lig. ) group(C). RESULTS: (1) Mean pulmonary axterial pressure (mPAP)of group B was significantly higher than that of group A and mPAP of group C was significantly lower than that of group B(P0.05); (2)Electron microscopy and immunohistochemistry showed ligustrazing could inhibit the diposition of col- lagenous fiber(collagen type Ⅰ )in pulmonary arterioles induced by hypoxic hypercapnia; (3) Plasma endothelin level of group C was significantly lower than that of group B (P

AIM: To study the effect of chronic hypoxic hypercapnia on expression of heme oxygenase-1(HO-1). METHODS: Sprague-Dawley rats were randomly divided into three groups: control group(A),hypoxic hypercapnic group(B), hypoxic hypercapnia+hemin group(C). HO-1 and HO-1 mRNA were observed in pulmonary arterioles by the technique of immunohistochemistry and in situ hybridization. RESULTS: ① mPAP and weight ratio of right ventricle(RV) to left ventricle plus septum (LV+S) were significantly higher in rats of B group than those of A and C group (P0.05). ② Blood CO concentration was significantly higher in rats of B group than that of A group(P

AIM: To observe the effects of Salvia miltiorrhiza Bge (SMB) on left ventricular hypertrophy(LVH)in spontaneously hypertensive rats (SHR) and the expression of c-fos. METHODS: 18 SHRs in 8 weeks old were divided into three groups at random. SMB or distilled water(1 g?kg -1?d -1)was injected intraperitoneally to two groups for 10 weeks. Systolic blood pressure (SBP) and left ventricular mass index(LVMI)were measured. HE,VG and immunohistochemical staining combined with computed morphometry were used to evaluated the cardiomyocyte size and diameter, the collagen volume fraction(CVF), perivascular circumferential area (PVCA) and c-fos expression in the left ventricular tissue. RESULTS: Compared with 8-week-old rats, the SBP, LVMI, cardiomyocyte size and diameter, CVF, PCVA, c-fos expression increased markedly in the 18th week of SHRs. The LVH stopped and c-fos expression decreased whereas SBP changed slightly in animals treated with SMB. CONCLUSION: Chronic treatment with SMB can inhibit the development of LVH in SHR, which is probably related to the decease of cardiac c-fos.

AIM: To investigate the effect of diltiazem on mean pulmonary arterial pressure(mPAP) and nitric oxide synthase(NOS) in arterioles in chronic hypoxic hypercapnic rats. METHODS: Twenty-four rats were randomly divided into three groups: control group(A),hypoxic hypercapnic group(B), hypoxic hypercapnia+ diltiazem group (C), constitutive endothelial NOS(ceNOS) were observed in arterioles of rats using the technique of immunohistochemistry,ceNOS mRNA were observed by the technique of in situ hybridization . RESULTS: (1)mPAP was significantly higher in rats of B group than that of A and C group( P 0 05),but mCAP was lower in rats of C group than that in B group.(2)Light microscopy showed WA/TA (vessel wall area/total area) was significantly lower in rats of C group than that of B group ( P