[The change of fractalkine in lung tissue of rat with hypoxic pulmonary hypertension].

OBJECTIVE: To evaluate the role of fractalkine in the pathogenesis of hypoxic pulmonary hypertension. METHODS: Twenty male SD rats were randomly divided into control group and hypoxic group. Rats in hypoxic group were exposed to hypoxia for 3 weeks. Mean pulmonary arterial pressure (mPAP) was measured by a right cardiac catheterization. The thickness of pulmonary arterioles was measured with a computerized image analyzer. The rates of wall thickness/external diameter (WT%) and wall area/total vascular area (WA%) were calculated. The fractalkine level in lung tissue were measured by enzyme-linked immunosorbent assay. Fractalkine mRNA expression in lung were observed by reverse transcriptase-polymerase chain reaction. RESULTS: The rat mPAP of hypoxic group was higher than that of the control group [(28.7 +/- 3.8) mmHg vs (16.3 +/- 2.1) mmHg, P < 0.01]. The WT% and WA% were increased significantly in hypoxic group than in control group (WT%: (21.28 +/- 4.60)% vs (10.20 +/- 1.56)%, WA%: (67.08 +/- 9.44)% vs (38.11 +/- 42.30)%, P < 0.01, respectively]. In hypoxic group, the expression of fractalkine mRNA in the lung was significantly up-regulated [(0.49 +/- 0.05) vs (0.29 +/- 0.02), P < 0.01], the expression level of fractalkine in lung tissue was higher than that in control group [(7622.6 +/- 938.4) pg/mL vs (4168.5 +/- 403.5) pg/mL, P < 0.01. Linear correlation analyses showed that fractalkine mRNA and protein were positively associated with WA% and WT% (P < 0.05). CONCLUSION: The synthesis and release of fractalkine are increase in the lung tissue of chronic hypoxic rats, and fractalkine may play an important role in hypoxic pulmonary hypertension.

[Effect of simvastatin on endothelin-1 expression in endothelial cell cultured hypoxically].

OBJECTIVE: To observe the role of simvasatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, in synthesis and excretion of endothelin-1 (ET-1) in endothelial cell cultured hypoxically. METHODS: Human umbilical vein endothelial cells were hypoxically cultured and treated with simvastatin by different concentrations (0, 1.0, 2.5, 5.0, 10.0 micromol/L) and different times (12, 24, 48 h). Mevalonate was used to intervent the effect of simvastatin. Reverse transcription-polymerase chain reaction (RT-PCR)and enzyme-linked immunoadsorbent assay (ELISA) were adopted to measure ET-1 mRNA and ET-1 in supernatant fluid of endothelial cell culture. RESULTS: (1) There were no changes of ET-1 mRNA and ET-1 expression after the hypoxically cultured endothelial cell were incubated with 1 MICROmol/L simvastatin, but ET-1 expression decreased without significant difference compared to control (0 micromol/L simvastatin) when interfered with 2.5 micromol/L simvastatin. The decreases of ET-1 mRNA and ET-1 expression became more obvious when expression were interfered by 5 micromol/Land 10 micromol/L simvastatin (P < 0.01). (2) ET-1 mRNA and ET-1 expression decreased at 12 h after the endothelial cells were incubated with 10 micromol/L simvastatin, which became more fewer at 24 h and reached the minimum expression at 48 h (P < 0.01). (3) The inhibition effect of simvastatin on ET-1 mRNA and ET-1 expression of endothelial cells could be prevented by mevalonate with concentration of 100 micromol/L. CONCLUSION: Simvastatin can inhibit ET-1 expression in endothelial cell cultured hypoxically.

[The change of fractalkine in serum and pulmonary arterioles of hypoxic rat].

OBJECTIVE: In order to evaluate the role of fractalkine in the pathogenesis of hypoxic pulmonary hypertension, we observed the change of serum soluble fractalkine and the expression of fractalkine in pulmonary arterioles of rat at different phase of hypoxia-induced pulmonary hypertension development. METHODS: The rat model of hypoxic pulmonary hypertension was duplicated by intermittent hypoxia. Mean pulmonary arterial pressure (mPAP) was measured by a right cardiac catheterization. The thickness of pulmonary arterioles was measured with a computerized image analyzer. Serum soluble fractalkine concentrations were measured by enzyme-linked immunosorbent assay. The expressions of fractalkine mRNA and protein in pulmonary arterioles were detected by in situ hybridization and immunohistochemical analysis, respectively. RESULTS: Compared to control, the mPAP of rats was markedly elevated after hypoxia for 14 days (P < 0.01), but the index of wall thickness of pulmonary arterioles (WT% and WA%) and the index of right ventricular hypertrophy CRV/(LV+S)] increased significantly at 21 days of hypoxia (P < 0.01). In rats exposed to hypoxia for 21 days, the fractalkine mRNA and protein levels in pulmonary arterioles were up-regulated significantly (P < 0.01), and the serum soluble fractalkine concentrations were also elevated (P < 0.01), as compared with control. Linear correlation analysis showed that the fractalkine mRNA level in pulmonary arterioles was associated with WA% (r = 0.749, P < 0.01) and WT% (r = 0.732, P < 0.01), the fractalkine protein level in pulmonary arterioles was also correlated with WA% (r = 0.727, P < 0.01) and WT% (r = 0.683, P < 0.01). CONCLUSION: The chronic hypoxia stimulates the synthesis and release of fractalkine. Fractalkine plays an important role in regulating the pulmonary vascular remodeling.

[Expression and clinical significance of matrilysin (MMP-7) in human rectal cancer].

OBJECTIVE: To detect the matrilysin (MMP-7) expression in human rectal cancer and to investigate whether it is correlated with invasion and metastasis of human rectal cancer. METHODS: The paired samples obtained from 100 inpatients were allocated into cancer group and control group. By Quantitative-Real-Time RT-PCR, immunohistochemical staining and computerized image analysis, the mRNA and protein expressions of MMP-7 in human rectal cancer were measured and further analyzed for the relationship between MMP-7 expression and clinicopathologic characters. RESULTS: MMP-7 mRNA expression in cancer group was higher than that in control group (P = 0.001), the mRNA expression ratio of 67 (7%) samples was over 1. The mRNA expression level of MMP-7 was correlated with age, Dukes's Staging, lymph node metastasis and histological differentiation grade. The positive degree of immunohistochemical staining for MMP-7 in cancer group (1.94 +/- 0.21) was higher than that in control group (1.15 +/- 0.20, P = 0.002). The protein expression of MMP-7 was correlated with age, Dukes's Staging and lymph node metastasis. CONCLUSION: MMP-7 expression in human rectal cancer increases significantly and plays a key role in the invasion and metastasis of human rectal cancer.

[The change of nuclear factor-kappa B expression in the lung tissues of chronic hypoxic rats].

OBJECTIVE: To investigate the change of nuclear factor-kappa B (NF-kappaB) expression in the lung tissues from chronic hypoxic rats and the role of NF-kappaB in the pathogenesis of hypoxic pulmonary hypertension. METHODS: Twenty male SD rats were randomly divided into two groups: control group and hypoxic group. The animal model of pulmonary hypertension was established by exposing the rats to normabaric hypoxic conditions for three weeks. The mean pulmonary arterial pressure (mPAP) was measured by a right cardiac catheterization. The indices of wall thickness of pulmonary arteriole (WT% and WA%) were measured by a computerized image analyzer. NF-kappaB expression in lung tissues were observed by using immunohistochemistry. RESULTS: (1) The mPAP of hypoxic rats was (29.1 +/- 4.5) mmHg,and it was (16.8 +/- 2.6) mmHg in normal rats, there was significant difference between two groups (P < 0.001). (2) In hypoxic group, the WT% was (22.36 +/- 2.99)% and WA% was (69.14 +/- 5.38)%; in normal group, WT% was (15.36 +/- 3.08)% and WA% was (46.75 +/- 6.54)%, the differences were significant (P < 0.01). (3) Both normal and hypoxic group, there were positive cells for NF-kappaB nuclear staining in lung tissues of rats. The percentage of positive cells for NF-kappaB nuclear staining in bronchiolar epithelial cells was significantly increased in the hypoxic group [(29.11 +/- 1.12)%] than that in the control group [(12.23 +/- 1.08)%], P < 0.001. CONCLUSION: NF-kappaB expression is increased in the lung tissue of rats with chronic hypoxia. It may play a role in the pathogenic process of hypoxic pulmonary hypertension.

[Research on Rho-kinase expression in pulmonary arterioles of rat exposed to hypoxia].

OBJECTIVE: To evaluate the expression and the role of Rho-kinase (ROCK I and ROCK II )in the development of hypoxic pulmonary hypertension of rat. METHODS: Thirty six of adult male SD rats were randomly divided into six groups; one group was exposed to air as normal control, the other five groups were exposed to isobaric hypoxia for 1 day, 3 days, 1 week, 2 weeks and 3 weeks respectively. Microtube method was used to measure the mean pulmonary arterial pressure (mPAP). The right ventricle (RV) and left ventricle plus atrial ventricular septum (LV+S) were isolated and weighed to calculate the value of RV/(LV+S). The amounts of Rho-kinase and Rho-kinase mRNA in rat pulmonary artery were determined by immunohistochemistry, in situ hybridization and image analysis. RESULTS: The mPAP and RV/(LV+S) values increased with time prolongation of rats exposed to hypoxia (P<0.05). The ratio of arteriole wall thickness/vascular external diameter(WT%) and vascular area/total vascular area(WA%) went forward to a height with exposing rats to hypoxia for a long time; WT% and WA% of hypoxia group rats exposed for 3 weeks were significantly higher than that of control group (P<0.05). All of ROCK I , ROCK II, ROCK I mRNA and ROCK II mRNA in pulmonary arterioles got the enhanced positive signals of immunohistochemistry staining or in situ hybridization with prolonging the time of rats exposed to hypoxia. The hypoxia group for 3 weeks got significantly stronger staining signals of Rho-kinase and Rho-kinase mRNA in pulmonary arterioles than that of control group (P<0.05). The positive staining of ROCK I , ROCK I mRNA, ROCK II or ROCK II mRNA in pulmonary arterioles all positively related with mPAP, WA% and WT% (r=0.404, 0.267 and 0.263; 0.500, 0.263 and 0.260; 0.490, 0.295 and 0.286; 0.579, 0.251 and 0.254) (P<0.05). CONCLUSIONS: Hypoxia led Rho-kinase and Rho-kinase mRNA to have an increased expression. Rho-kinase may play a role in the development of hypoxic pulmonary hypertension by contracting and remodeling pulmonary arterioles.

[Preventive effects of montelukast on the collagen expression of pulmonary arterioles in rats with chronic hypoxia].

OBJECTIVE: To evaluate the preventive effects of montelukast on the collagen expression of pulmonary arterioles in chronic hypoxic rats. METHODS: Thirty male Wistar rats were randomly divided into three groups: control group, hypoxic group and montelukast preventive group. The animal model of pulmonary hypertension was established by exposing the rats to normabaric hypoxic conditions 8 hours q.d. for 3 weeks. The expression levels of collagen I and III in arterioles were observed by immunohistochemistry. RESULTS: The positive degree of collagen I in pulmonary arterioles of hypoxic group was higher than that of control group (1.51+/-0.09 vs 1.15+/-0.05, P<0.01), and the positive degree of collagen I in pulmonary arterioles of preventive group (1.19+/-0.06) was lower than that of hypoxic group (P<0.01). The differences of positive degree of collagen III in pulmonary arterioles were not significant among the three groups (P>0.05). CONCLUSION: Montelukast can reduce the hypoxia-induced deposition of collagen I in the pulmonary arterioles wall.

[Preventive effects of urapidil on hypoxic pulmonary hypertension in rats].

OBJECTIVE: To investigate the preventive effect of urapidil, an alpha 1-adrenoceptor antagonist, on hypoxic pulmonary vascular remodeling. METHODS: Twenty-one male Sprague-Drawley rats were randomly allocated into three groups: control group, hypoxic group and hypoxic plus urapidil group. The animal model of hypoxic pulmonary hypertension was established by exposing the rats to normobaric hypoxic condition for three weeks, and the rats of hypoxic plus urapidil group were treated with urapidil 10 mg/kg before and after hypoxic processing. The right ventricle (RV) and left ventricle plus septum (LV + S) of rat were weighed respectively, and the RV/(LV + S) was calculated. The wall thickness(WT) and wall area(WA) of pulmonary arterioles wall were measured by a computerized image analyzer, and the index of wall thickness of rats pulmonary arterioles-the percentages of the wall thickness in the external diameter (WT%) and the wall area in the total vascular area (WA%) were calculated. RESULTS: In the hypoxic group, RV/(LV + S), WT% and WA% were (33.06 +/- 1.74)%, (25.15 +/- 1.47)% and (73.88 +/- 2.93)% respectively, while in the control group, they were (23.21 +/- 2.31)%, (13.55 +/- 1.60)% and (48.23 +/- 4.43)%, the difference between the two groups was significant (P < 0.01). In the hypoxic plus urapidil group, they were (26.63 +/- 1.44)%, (14.57 +/- 2.27)% and (52.68 +/- 3.98)%, being remarkably decreased as compared with those in the hypoxic group (P < 0.01). CONCLUSION: Urapidil can prevent hypoxic pulmonary hypertension.