AIM: To investigate the role of Ca2+ - activated, delayed - rectifier and ATP sensitive K+ channel (KCa, Kdr, KATP) in airway hyperresponsiveness of asthmatic guinea pigs. METHODS: The method of recording the tone of isolated trachea rings was performed, and the changes of dose-response curves of trachea rings to histamine caused by different K+ channel blockade were investigated. RESULTS: (1) After inhibition of KCa, by tetraethylammonium (TEA) , the dose - response curve of trachea rings to histamine did not change in control group, while the maximal contraction of trachea rings to 10-4 mol/L and 10-3 mol/L histamine decreased significantly ( P

Immediate patency assessment of a completed microvascular anastomosis is considered an essential step in a microsurgical procedure. The most frequently used patency test is the milking patency test, which is too traumatic for use in clinical microsurgery. An atraumatic patency test remains to be devised. According to the principle of mechanics that rolling friction is smaller than sliding friction, we designed the so-called rolling patency test. The femoral arteries of Wistar rats were used in the experimental study to make a comparison between the two patency tests. The result showed that intact endothelial cells covered more than 90% of the inner wall of the artery in the rolling patency test, but less than 25% in the milking patency test. The study suggests that the rolling patency test is a reliable and atraumatic immediate patency test for use in clinical microsurgery.

AIM: To investigate the molecular mechanism by which hypoxia affect the endothelial nitric oxide synthase (eNOS) expression in cerebral artery endothelial cells (CAECs). METHODS: Primary cultured porcine CAECs were exposed to hypoxia for 2 h, 6 h, 12 h, 24 h and 48 h. The eNOS mRNA level was determined by RT-PCR. The level of eNOS protein was detected by Western blotting. After specific PKC inhibitors BIM Ⅰ(1 ?mol/L) and G6983 (1 ?mol/L) were added, CAECs were exposed to hypoxia for 24 h. The effect of hypoxia on eNOS mRNA stability was analyzed after actinomycin D was added. RESULTS: After exposure to hypoxia for 2 h, the levels of eNOS mRNA and protein in CAECs were increased. The levels of eNOS mRNA and protein reached peak after 12 h of hypoxia (about 2 5 fold and 2 0 fold, respectively, compared to control), and remained at higher level even after 48 h of hypoxia. Moreover, hypoxia did not change the stability of eNOS mRNA. The specific PKC inhibitors BIM Ⅰ and G6983 attenuated significantly the effects of hypoxia on eNOS gene expression. CONCLUSION: These results suggest that hypoxia may enhance the expression of eNOS gene in CAECs through PKC signaling pathway, which might be one of the mechanisms of cerebral artery dilation and neuroprotection during cerebral hypoxia.

AIM:To investigate the role of potassium channel expression alteration in chronic cigarette smoking-induced increase in pulmonary vascular responsiveness,the effect of chronic cigarette smoking on large-conductance calcium-activated potassium channel(BKCa) and voltage-dependent delayed rectifier potassium channel(Kv1.5) expression in rat pulmonary smooth muscle cells were investigated in vivo.METHODS: HE staining,immuno-histochemistry and in situ hybridization techniques were used.RESULTS:(1) Chronic cigarette smoking downregulates the protein and mRNA expression of BKCa in pulmonary arterial smooth muscles.(2) Chronic cigarette smoking downregulated the protein and mRNA expression of Kv1.5 in pulmonary arterial smooth muscles.(3) In big artery,BKCa decreased more makedly than Kv1.5,but in small artery,both of them decreased equally.CONCLUSION: Chronic cigarette smoking downregulates the levels of BKCa and Kv1.5 in rat pulmonary arterial smooth muscle cells in vivo,which maybe contribute to the mechanism of cigarette smoking-induced increase in pulmonary vascular responsiveness.

AIM: To explore the effects of 5-HT and electrolytes on the airway remodeling in guinea pigs with bronchial asthma.METHODS: 70 guinea pigs were divided into 7 groups: control group,model group,continued model group,5-HT group,anti-5-HT group,high Mg~(2+) group,low Mg~(2+) group.Remodeling model was established with ovalbumin.RESULTS: ① In model group,5-HT of serum and thickness of airway walls were significantly increased compared with control group(P

the normal control group (Pthe continued asthma model group (P

To construct an eukaryotic expressing vector that expresses CH50, a recombinant CellⅠ-HepⅡ bifunctional-domain polypeptide of human fibronectin, and to investigate the chemotaxis to immune cells and the inhibitory effect on the growth of tumor by the expression of the plasmid in vivo, the plasmid was constructed by DNA recombination. Gene transfection was performed in vitro and in vivo. The expressed product was identified by Western blot. The chemotaxis after gene transfection in vivo was observed by histotomy and staining of muscle tissues. The inhibition of gene transfection on solid tumor was observed in mice. The results showed that plasmid pCH510 was constructed by the recombination of the 5′-terminal noncoding region and signal peptide coding region of human fibronectin cDNA and cDNA fragment coding CH50 polypeptide with a 3′-terminal noncoding region of human FN cDNA, and the insertion of the recombinated fragment into plasmid pcDNA3.1. After transfection with plasmid pCH510, NIH3T3 cells could produce CH50 polypeptide. The transfection of plasmid pCH510 by the injection in muscle of mouse could produce the effects of chemotaxis on immune cells and the inhibition on the growth of solid tumor. It is concluded that plasmid pCH510 can express in cells and in vivo in mouse. The expression of the plasmid in vivo has a chemotactic effect on immune cells and can inhibit the growth of solid tumor.

To construct an eukaryotic expressing vector that expresses CH50, a recombinant CellⅠ-HepⅡ bifunctional-domain polypeptide of human fibronectin, and to investigate the chemotaxis to immune cells and the inhibitory effect on the growth of tumor by the expression of the plasmid in vivo, the plasmid was constructed by DNA recombination. Gene transfection was performed in vitro and in vivo. The expressed product was identified by Western blot. The chemotaxis after gene transfection in vivo was observed by histotomy and staining of muscle tissues. The inhibition of gene transfection on solid tumor was observed in mice. The results showed that plasmid pCH510 was constructed by the recombination of the 5′-terminal noncoding region and signal peptide coding region of human fibronectin cDNA and cDNA fragment coding CH50 polypeptide with a 3′-terminal noncoding region of human FN cDNA, and the insertion of the recombinated fragment into plasmid pcDNA3.1. After transfection with plasmid pCH510, NIH3T3 cells could produce CH50 polypeptide. The transfection of plasmid pCH510 by the injection in muscle of mouse could produce the effects of chemotaxis on immune cells and the inhibition on the growth of solid tumor. It is concluded that plasmid pCH510 can express in cells and in vivo in mouse. The expression of the plasmid in vivo has a chemotactic effect on immune cells and can inhibit the growth of solid tumor.

Summary: The expression of CH50 polypoptide in bladder cancer cell line BIU-87 and the effects on the invasion ability of BIU-87 were investigated. The eukaryotic expressing vector pCH510 of polypeptide CH50 was introduced into BIU-87 cells by gene transfection in vitro. The expression of CH50 polypeptide was detected by using immunohistochemical S-P method. The expression of the transfected gene was identified by RT-PCR. Cell invasion assay kit was applied to detect the effect of CH50 polypeptide on the invasion ability of BIU-87. The results showed that the BIU-87 cells transfected with pCH510 could express the CH50 polypeptide, while in the control group, no CH50 polypeptide was detectable. In the transfection group, the invasion ability of BIU-87 in vitro was lower than in control group (P<0.05). It was concluded that CH50 polypeptide was successfully expressed in BIU-87 cells by gene transfection, by which the in vitro invasion ability of BIU-87 was inhibited.

OBJECTIVETo investigate the antioxidant and anti-endotoxin effects of propofol on endothelial cells and the possible mechanisms.

METHODSCultured endothelial cells were treated with hydrogen peroxide (H(2)O(2)), propofol + H(2)O(2), lipopolysaccharide (LPS) and propofol + LPS, respectively. Endothelial cell damage was monitored for possible lactic dehydrogenase (LDH) release. The transcription and the protein expression levels of endothelial nitric oxide synthase (eNOS) were measured.

RESULTSLDH release was higher in groups treated with H(2)O(2) or LPS than in the control group. After pretreatment with propofol, the effects induced by H(2)O(2) were attenuated, but propofol did not decrease the LDH release induced by LPS. Both H(2)O(2) and LPS significantly increased the eNOS transcript levels and the increases were significantly attenuated after pretreatment with propofol. Both H(2)O(2) and LPS significantly increased the eNOS protein expression and the increase was attenuated after pretreatment with propofol.

CONCLUSIONPropofol could protect endothelial cells against oxidative stress by inhibiting eNOS transcription and protein expression, but could not antagonise endotoxin induced cell injuries.

Antioxidants ; pharmacology ; Endothelium, Vascular ; cytology ; drug effects ; metabolism ; Endotoxins ; antagonists & inhibitors ; Free Radical Scavengers ; pharmacology ; Humans ; In Vitro Techniques ; Lipopolysaccharides ; pharmacology ; Nitric Oxide ; pharmacology ; Nitric Oxide Synthase ; biosynthesis ; Nitric Oxide Synthase Type III ; Propofol ; pharmacology