AIM: The aim of this study is to investigate the possible role of potassium channel in hypoxic pulmonary vasoconstriction (HPV). METHODS: Fresh human lung tissues were obtained from the Division of Chest Surgery to establish a human model of HPV in vitro. Three groups, control group, COPD group and COPD plus chronic hypoxia group were divided. Human isolated pulmonary artery rings and specific blocking agent corresponding to K_V, K_ Ca, K_ ATP were used to investigate the possible role of the potassium channel in HPV. RESULTS: (1) In acute hypoxia, the vascular ring tension in three groups all increased (P

AIM: To investigate the role of intracellular free Ca2+ concentration ([Ca2+]i) in the regulation of calcium-activated chloride (ClCa) channels in pulmonary artery smooth muscle cells (PASMCs) of rats under normoxic, acute and chronic hypoxic conditions. METHODS: Acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca2+ indicator Fura-2/AM was used to observe [Ca2+]i of rat PASMCs in normal and chronic hypoxic condition. The influences of ClCa channels on PASMCs proliferation were assessed by MTT assay. RESULTS: (1) The ClCa channel blockers niflumic acid (NFA) and indaryloxyacetic acid (IAA-94) produced inhibitory effects on acute hypoxia-evoked contractions in pulmonary artery. (2) Under chronic hypoxic condition, [Ca2+]i was increased. In normoxic condition, [Ca2+]i was (123.63?18.98) nmol/L, and in hypoxic condition, [Ca2+]i was (281.75?16.48)nmol/L (P0.05). (4) Chronic hypoxic increased [Ca2+]i which opened ClCa channels. The NFA and IAA-94 blocked them and decreased [Ca2+]i from (281.75?16.48)nmol/L to (117.66?15.36)nmol/L (P

To investigate the relationship between intracellular free Ca2+ concentration ([Ca2+]i) and calcium-activated chloride (Clca) channels of pulmonary artery smooth muscle cells (PASMCs) in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca2+ indicator Fura-2/AM was used to observe [Ca2+]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid (NFA) and indaryloxyacetic acid (IAA-94) exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca2+]i was increased. Under normoxic condition, [Ca2+]i was (123.63 +/- 18.98) nmol/L, and in hypoxic condition, [Ca2+]i was (281.75 +/- 16.48) nmol/L (P<0.01). Under normoxic condition, [Ca2+]i showed no significant change and no effect on Clca channels was observed (P> 0.05). Chronic hypoxia increased [Ca2+]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca2+]i from (281.75 +/- 16.48) nmol/L to (117.66 +/- 15.36) nmol/L (P<0.01). MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency (A value) from 0.459 +/- 0.058 to 0.224 +/- 0.025 (P<0.01). Hypoxia increased [Ca2+]i which opened Clca channels and had a positive-feedback in [Ca2+]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.

Objective To investigate the correlation of microperimetric parameters,best-corrected visual acuity (BCVA) and central retinal thickness (CRT) in diabetic macular edema (DME) eyes.Methods It is a prospective,no controlled,open study.Twenty-four consecutive patients (40 eyes) with DME were included.There were 10 males (18 eyes),14 females (22 eyes);aged from 41 to 79 years,with the mean age of (56.84±8.96) years.All the patients were type 2 diabetes,the average duration of diabetes was 8 years.BCVA was evaluated using the international Snellen E vision test chart,and then recorded as logarithm of the minimum angle of resolution (logMAR).CRT was measured by Cirrus HD-OCT4000.MAIA microperimetric parameters were evaluated,including average threshold (AT) of retinal sensitivity,macular integrity index (MI),fixating points within a circle of 1° (P1) and 2° of radius (P2),bivariate contour ellipse area (BCEA) considering 63％ and 95％ of fixating points (A63,A95),and horizontal and vertical axes of that ellipse (H63,H95,V63,V95).Pearson correlation analysis was performed to evaluate the association between these variables.The independent factor influenced the type of fixation was analyzed by multiple linear regression analysis.Results Strong correlations of logMAR BCVA with CRT (r=0.58,P=0.000),V63 (r=0.44,P=0.004),V95 (r=0.41,P=0.008),MI (r=0.36,P=0.024),AT (r=-0.61,P=0.000),P1 (r=-0.41,P=0.009),P2 (r=-0.38,P=0.015) were found.AT was correlations with P1 (r=0.53,P=0.000),P2 (r=0.51,P=0.001),A63 (r=-0.39,P=0.012),A95 (r=-0.40,P=0.012),V63 (r=-0.53,P=0.000),V95 (r=-0.46,P=0.003),MI (r=-0.50,P=0.001).There was no correlation between AT and CRT (r=-0.21,P=0.190).Forty eyes were included in this study,8 eyes (20％) had stable fixation,14 eyes (35％) had relatively unstable fixation,18 eyes (45％)had unstable fixation.Multiple linear regression analysis showed that fixation classification was independently affected by P 1.Conclusions In DME eyes,logMAR BCVA was positively correlated with CRT,negatively correlated with AT,P1 and P2.There is no correlation between AT and CRT.The fixation classification was independently affected by P 1.

AIM: To investigate the contribution of diazoxide,an opener of mitochondrial ATP-sensitive K+ channel(MitoKATP),and mitochondrial membrane potential(??m) to change of H2O2 in rat pulmonary artery smooth muscle cells(PASMCs) and to unbalance between cell proliferation and apoptosis of PASMCs induced by hypoxia.METHODS: The rat PASMCs were isolated from fresh normal lung tissues and cultured,which were divided into 6 groups,as follows: ① control group;② diazoxide group;③ 5-HD group;④chronic hypoxia group;⑤ chronic hypoxia+diazoxide group;⑥ chronic hypoxia +5-HD group.The relative change in mitochondrial potential was detected with rhodamine fluorescence(R-123) technique.The level of H2O2 in rat PASMCs was detected with chemiluminescence method.The proliferation of rat PASMCs was examined by cell cycle analysis and MTT colorimetric assay.RESULTS: After exposed to diazoxide for 24 h,the intensity of R-123 fluorescence,the level of H2O2 and the A value in normoxic rat PASMCs were significantly increased,and the apoptosis of rat PASMCs was significantly decreased as compared with control group(P

Objective To investigate the feasibility of Ad-hTGF-β1 transfected bone marrow mesenchymal stem cell(BMSCs) into chondrocytes differentiation and the change of TAZ mRNA. Methods Rats BMSCs were obtained and cultured by whole bone marrow method, and then the third-generation cells were seeded into cell culture plate, and divided into three groups:Ad-hTGF-β1 transfected group,Ad-EGFP transfected group and the control group. The control group was added in common medium without any treatment while the other two groups were respectively added in serum-free medium containing Ad-hTGF-β1 or that containing Ad-EGFP. Seven days later, real-time fluorescent quantitation PCR and Western blot were employed for detecting the expression of TGF-β1 ,while immunohistochemical and Western blot for the expression of collagen Ⅱ , and real-time fluorescent quantitation PCR for the expression of TAZ mRNA. Results Seven days after the transfection, real-time fluorescent quantitation PCR revealed that the average relative expression of TGF-β1 was:Ad-hTGF-β1 group 0.863, Ad-EGFP group 0.183, and the control group 0.180; The average relative expression of TAZ was:Ad-hTGF-β1 group 0.810, Ad-EGFP group 0.416, and the control group 0.366.The expression difference of TGF-β1 and TAZ were statistically significant (P ＜ 0.05). Western blot and immunohistochemical proved strong collagen Ⅱ expression in Ad-hTGF-β1 group while it was detected a little in the other two groups. Conclusion BMSCs could be successfully and stably induced into chondrocytes differentiation by Ad-hTGF-β1. Meanwhile, the mRNA of TAZ is up regulate during the differentiation,so it is suppose that TGF-β1 improve BMSCs into chondrocytes differentiation by TAZ.

Objective To explore the effects of Sodium Nitroprusside(SNP) on apoptosis of airway smooth muscle cells(ASMCs) of asthmatic rats in vitro.Methods Ten Wister rats were selected to make the models of asthma.The effect of SNP on the survival rate of asthmatic rat airway smooth muscle cells was detected by MTT method.The apoptosis of cells was detected by TUNEL method and flow cytometry.Results Comparing with asthma group,the survival rate of ASMCs was decreased significantly in SNP plus asthma group by MTT method(P

AIM:To investigate NO-donor sodium nitroprusside(SNP)-induced apoptosis of human airway smooth muscle cells(HASMCs) of passive sensitization by serum from allergic asthmatic patients.METHODS: The technique of human airway smooth muscle(HASMCs) passively sensitized with serum from allergic asthmatic patients was adopted.The effect of SNP on the survival rate of passively sensitized HASMCs was detected by MTT method.Apoptosis of cells was detected by TUNEL and flow cytometry.RESULTS:(1) Compared to sensitized group,the survival rate of passively sensitized HASMCs decreased in SNP+sensitized group(n=5,P

Aim To investigate the effects of dipfluzine(Dip) on proliferation and collagen synthesis in cultured neonatal rat cardiac fibroblasts(CFB)stimulated by angiotensin Ⅱ(AngⅡ),and to explore the action mechanisms of dipfluzine.Methods CFB were treated with AngⅡ to induce fibrosis model.The effect of Dip on proliferation of CFB was observed by MTT coloricmetric assay;synthesis of collagen was observed by the hydroxyproline concentration detemined;cell cycle distribution and PCNA proein were determined with flow cytometer(FCM);The expression of collagenⅠmRNA,collagen Ⅲ mRNA and TGF-?_1 mRNA was examined using semi-quantitative RT-PCR analysis;The protein expression of cPKC? and ERK_1 in CFB was observed by immunohistochemical staining.Results ① Within a concentration coverage,Dip inhibited CFB proliferation and collagen synthesis(P

To investigate the relationship between intracellular free Ca2+ concentration ([Ca2+]i)and calcium-activated chloride (Clca) channels of pulmonary artery smooth muscle cells (PASMCs) in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca2+indicator Fura-2/AM was used to observe [Ca2+]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay.The Clca channel blockersniflumic acid (NFA) and indaryloxyacetic acid (IAA-94) exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca2+ ]i was increased. Under normoxic condition, [Ca2+]i was (123.63±18.98) nmol/L, and in hypoxic condition, [Ca2+]i was (281. 75±16.48) nmol/L (P＜0.01). Under normoxic condition, [Ca2+]i showed no significant change and no effect on Clca channels was observed (P＞0. 05). Chronic hypoxia increased [Ca2+]i which opened Clca channels. The NFA and IAA-94blocked the channels and decreased [Ca2+]i from (281. 75±16.48) nmol/L to (117.66±15.36)nmol/L (P＜0.01). MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency (A value) from 0. 459±0. 058 to 0. 224±0. 025 (P＜0.01).Hypoxia increased [Ca2+]i which opened Clca channels and had a positive-feedback in [Ca2+]i. Thismay play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition,Clca channel may play a part in the regulation of proliferation of PASMCs.