Secular trends of asthma mortality in China and the United States from 1990 to 2019 / 中华医学杂志(英文版)

BACKGROUND@#Asthma imposes a large healthcare burden in China and the United States (US). However, the trends of asthma mortality and the relative risk factors have not been comparatively analyzed between the countries. The aim of this study was to compare the mortality and risk factors between China and the US.@*METHODS@#The deaths, and mortality rates of asthma in China and the US during 1990-2019 were obtained from the Global Burden of Disease Study 2019. The age-period-cohort model was used to estimate these mortality rates based on a log-linear scale with additive age, period, and cohort effects. The population attributable fractions of risk factors for asthma were estimated.@*RESULTS@#In 1990-2019, the asthma mortality rate was higher in China than in the US. The crude and age-standardized asthma mortality rates trended downward in both China and the US from 1990 to 2019. The decline in mortality was more obvious in China. Mortality gap between the two countries was narrowing. A sex difference in asthma mortality was observed with higher mortality in males in China and females in the US. The age effects showed that mortality increased with age in adults older than 20 years, particularly in the elderly. Downward trends were generally observed in the period and cohort rate ratios in both countries, with China experiencing a more obvious decrease. Smoking and high body mass index (BMI) were the leading risk factors for asthma mortality in China and the US, respectively. Mortality attributable to occupational asthmagens and smoking decreased the most in China and the US, respectively.@*CONCLUSIONS@#In 1990-2019, the asthma mortality rate was higher in China than in the US; however, the mortality gap has narrowed. Mortality increased with age in adults. The improvements in asthma death risk with period and birth cohort were more obvious in China than in the US. Smoking, high BMI, and aging are major health problems associated with asthma control. The role of occupational asthmagens in asthma mortality underscores the importance of management and prevention of occupational asthma.

Dietary nutrition status of soldiers living at high altitude / 军事医学

Objective To investigate the dietary nutrition status of plateau frontier forces and to make recommendations on food and nutrients intake for plateau forces.Methods The dietary status of the plateau forces located at an altitude of 4600 m and 4030 m was investigated by weighing method.The dietary ration for soldiers, their daily dietary allowance and dietary balance index were used to evaluate their dietary patterns and nutrient intake.The concentrations of serum vitamin A and 25-OH vitamin D(25-OH VD) were detected by high performance liquid chromatography (HPLC).The arm muscle circumference and body fat rate of soldiers were evaluated by GJB 1636A-2016 and body composition related standard respectively.Results The intake of eggs, milk and plant oil of Unit A was sufficient, while the rest of the food intake did not reach the military standard;The intake of grain and plant oil of Unit B was sufficient,but the rest of the food intake was insufficient.The intake of protein,calcium,phosphonium,sodium,iron,selenium,iodine,copper,manganese,vitamin E and vitamin B3 of Unit A were adequate, but that of energy,potassium,zinc,magnesium,vitamin D,vitamin C,vitamin B1 and vitamin B2 was insufficient, and the intake of vitamin A,vitamin B6,vitamin B9 and vitamin B12 of Unit A was deficient.The intake of energy, protein,vitamin E,vitamin C,vitamin B1 and vitamin B3,and most of the minerals was adequate in Unit B, but vitamin B2 was insufficient.Furthermore, the intake of calcium,iodine,vitamin A,vitamin D and vitamin B was deficient.The proportion of nutrients which supply energy and the energy distribution of three meals in the two units were imperfect.The concentration of plasma vitamin A in both units was sufficient,but the concentration of plasma 25-OH VD was deficient.93.5% soldiers of unit A and 97.7% soldiers of unit B reached the standard of proper muscle circumference,80.6% soldiers of unit A and 70.5% soldiers of unit B had a low body fat rate.Conclusion The dietary structure of plateau border forces is not balanced.The intake of some foods and nutrients is insufficient so that nutritional education is badly needed to improve the dietary status of plateau forces.

Investigation into the nutritional knowledge, attitude and practices among officers and soldiers living at high altitude and its influential factors / 解放军医学杂志

Objective To investigate the levels of nutritional knowledge, attitude and dietary habits and its influential factors of the officers and soldiers in frontier forces to provide the theory basis for nutrition education.Methods Using self-designed nutritional knowledge-altitude-practice (KAP) questionnaires to survey 90 officers and soldiers who lived in plateau for at least 6 months. Questionnaires were handed out and handed over on the spot. According toMilitary Nutrition Survey and Evaluation Methods (GJB 1636A-2016), we measured the physical index of officers and soldiers, including height, weight and skin thickness of triceps. And we also evaluated body mass index (BMI) and upper arm muscle circumference.Results Nutrition knowledge, attitude and practice conditions of plateau forces were at the average, better and average levels respectively. Nutritional knowledge was significantly positively related to the practices (r=0.283,P=0.003), and was also significantly positively related to the age of the soldiers (r=0.228,P=0.04). Nutritional attitude was positively related to source of officers and soldiers (r=0.339,P=0.035), and nutritional practices were positively related to the upper arm muscle circumference (r=0.222,P=0.030). 65.6% of the officers and soldiers would like to know the knowledge about relationship between diet and disease. 25.6% of the officers and soldiers in the plateau were alcohol users.Conclusions Although the nutrition knowledge of plateau forces were poor, and the nutritional practices were influenced by nutritional knowledge, but the soldiers' attitude of changing unhealthy dietary habits was very positive. It is necessary to undertake the dietary nutrition education related to the high altitude nutrition among plateau forces to guild their nutritional practice scientifically.

The correlation of vitamin D level and vitamin D-binding protein gene polymorphism in chronic obstructive pulmonary disease / 中华内科杂志

Objective To assess the correlation of serum 25-hydroxyvitamin D (25-OHD) levels with vitamin D-binding protein (the group-specific component,GC) gene polymorphism in chronic obstructive pulmonary disease (COPD).Methods In a cross-sectional case-control study,250participants,including 116 COPD patients with smoking history and 134 healthy smokers,were investigated.A questionnaire about smoking history,vitamin D intake and comorbidities was collected.General pulmonary function was done by routine.Serum 25-OHD levels were detected by ELISA.The genetic variants (rs4588and rs7041) were genotyped by real time fluorescence polymerase chain reaction (RT-PCR) with TaqMan probe technology.Results The COPD patients had lower serum vitamin D level than the smoker subjects (36.58 nmol/L vs 43.80 nmol/L,P ＜0.001).In the COPD patients,vitamin D level was 39.43 nmol/L in those with percentage of predicted forced expiratory volume in 1 second (FEV1 ％ pred) greater than or equal to 80％.In other groups with FEV1 ％ pred 50％-80％,30％-50％ and lower than 30％,vitamin D levels were 35.32 nmol/L,32.21 nmol/L,26.25 nmol/L respectively (P ＜ 0.01).Moreover,there was a significant relevance of 25-OHD levels with FEV1 ％ pred in both COPD patients and healthy smokers (r2 =1.911; P ＜0.000 1).The mean 25-OHD concentration had a negative correlation with Global Initiative for Obstructive Lung Disease (GOLD) stages.Homozygous carriers of vitamin D-binding protein gene rs7041 T allele were independently related to 25-OHD levels and susceptibility of COPD (P ＜ 0.01 ; OR =2.140,95％ CI 1.157-3.959,P =0.015 respectively).Conclusions Patients with COPD are at high risk of vitamin D deficiency and the severity of COPD is inversely correlated with vitamin D levels.Furthermore,homozygous carrier of rs7041 T allele influences 25-OHD serum levels and is related to susceptibility of COPD,which may be a potential candidate gene for screening COPD.

Surfactant protein a polymorphism is associated with susceptibility to chronic obstructive pulmonary disease in Chinese Uighur population / 华中科技大学学报（医学）（英德文版）

This study investigated the correlation between surfactant protein-A (SP-A) polymorphism and the susceptibility of chronic obstructive pulmonary disease (COPD) in Xinjiang Uighurs. Genomic DNA was extracted from peripheral blood of 194 COPD smokers and 201 healthy smokers of Uighur who were hospitalized in or paid a visit to one of the four Xinjiang-based hospitals involved in the study, from March 2009 to December 2010. Single nucleotide polymorphisms (SNPs) were studied at aa62 (CCA/CCG rs1136451) and aa219 (CGG/TGG, rs4253527) in SP-A. Genotypes were determined by using the TaqMan polymerase chain reaction (PCR). Our results showed that genotype frequencies were different between the COPD and normal smokers in aa62 (x (2)=6.852, P=0.033). There were also significant differences in allele genotype frequencies between the COPD and the control and allele G might decrease the risk COPD (x (2)=6.545, P=0.011; OR=0.663; 95% CI: 0.484-0.909). The result suggested that polymorphism of aa62 (CCA/CCG, rs1136451) of SP-A may be associated with the susceptibility to COPD in Xinjiang Uighurs.

The expression of macrophage migration inhibition factor in pulmonary tissues of smokers with or without chronic obstructive pulmonary disease / 中华内科杂志

Objective To investigate the expression of macrophage migration inhibition factor (MIF) in pulmonary tissues of the smokers with and without chronic obstructive pulmonary disease (COPD).Methods The subjects were assigned into three groups:non-smokers without COPD (control group,n =12),smokers without COPD (smoker group,n =13) and smokers with COPD (COPD group,n =16).The specimens were obtained from lung tissues as far away from cancer focus as possible (＞ 5cm).Real-time quantitative PCR and immunohistochemistry were used to investigate the expression and distribution of MIF in pulmonary tissues.The relationship between the severity of airflow obstruction and the differential expressions of MIF in lung tissues of the smokers with or without COPD was analyzed.Results (1) MIF mRNA expression in COPD group (4.87 ± 1.79) was higher than that in the smoker group (2.16 ±0.72;P＜0.01),which was higher than that in the control group (1.09 ±0.48;P ＜0.01).(2)Immunohistochemistry analysis showed that MIF protein expression in lung tissues of the COPD group (0.277±0.025) was higher than that in the smokers group (0.199 ±0.034;P ＜0.01),which was significantly higher than that in control group (0.130 ±0.021 ;P ＜0.01).(3) Correlation analysis of MIF mRNA expression in the lung tissues and pulmonary function parameters of forced expired volume in one second (FEV1) percentage of predicted (FEV1 pred) and ratio of FEV1 to forced vital capacity (FEV1/FVC) suggested that MIF mRNA expression in the lung tissues was negatively related with FEV1 pred (r=-0.578,P ＜ 0.01) and FEV1/FVC (r =-0.607,P ＜ 0.01).Conclusions MIF expression significantly increases in the smokers with COPD,and MIF level in the lung is positively correlated with airflow limitation.The results suggest that MIF may play an important role in the pathogenesis of smokinginduced COPD.

Comparative study on the efficacy of tiotropium bromide inhalation and oral doxofylline treatment of moderate to severe stable chronic obstructive pulmonary disease / 华中科技大学学报（医学）（英德文版）

This study compared the efficacy and safety of tiotropium bromide inhalation powder (spiriva) and doxofylline oral tablet (doxofylline) in the treatment of chronic obstructive pulmonary disease (COPD). A multi-center, randomized, double-blind, double-dummy, parallel-controlled study involved 127 eligible stable moderate to severe COPD patients treated with inhaled tiotropium dry powder (18 μg/day) or oral doxofylline tablets (0.2 g/time, 2 times a day) for 12 and 24 weeks. Before and after treatment for 12 weeks and 24 weeks, respectively, pulmonary function, 6-min walking distance and dyspnea index were recorded. The results showed that in both tiotropium group and doxofylline groups, after 12-week treatment, FEV(1), FEV(1)/FVC% and 6-min walk distance were significantly higher than those before the medication, while dyspnea index decreased as compared with that before treatment. After 24-week treatment, a slight improvement in the measures was observed as compared with that of 12-weeks treatment, but the difference was not statistically significant. With both 12-week and 24-week treatment, the effect of tiotropium was slightly better than that of doxofylline tablets, with the difference being statistically insignificant. The major adverse events in the tiotropium group and doxofylline group were observed in 9 cases (9.9%) and 12 cases (12.9%), respectively, and no statistically significant difference was found between them. We are led to conclude that both tiotropium at 18 μg a day and doxofylline tablets at 0.2 g/day (two times a day) are effective and safe for the treatment of COPD.

Changes of protein kinase Calpha and cyclin D1 expressions in pulmonary arteries from smokers with and without chronic obstructive pulmonary disease / 华中科技大学学报（医学）（英德文版）

The purpose of this study was to investigate the changes of protein kinase Calpha (PKCalpha) and cyclin D1 expressions in pulmonary arteries from smokers with normal lung function and smokers with mild to moderate chronic obstructive pulmonary disease (COPD). The peripheral lung tissues were obtained from 10 non-smokers with normal lung function (non-smoker group), 14 smokers with normal lung function (smoker group), 11 smokers with mild to moderate COPD (COPD group). The morphological changes of pulmonary arteries were observed by HE-staining. The expressions of alpha-smooth muscle actin (alpha-SMA), proliferating cell nuclear antigen (PCNA), PKCalpha and cyclin D1 proteins in pulmonary artery smooth muscle cells (PASMCs) were immunohistochemically determined. The percentages of PCNA-positive cells were taken as the smooth muscle cells proliferation index (PI). The mRNA expressions of PKCalpha and cyclin D1 in PASMCs were evaluated by real-time fluorescence PCR. Morphometrical analysis showed that the ratio of pulmonary artery wall area to total area (WA%) in smoker group and COPD group was significantly greater than that in non-smoker group (P<0.01). The PASMCs proliferation index in smoker group and COPD group was significantly higher than that in nonsmoker group (P<0.01). The protein levels of PKCalpha and cyclin D1 in PASMCs were significantly increased in smoker group and COPD group as compared with non-smoker group (P<0.01). The mRNA expressions of PKCalpha and cyclin D1 in PASMCs were significantly elevated in smoker group and COPD group as compared with non-smoker group (P<0.01). Significant correlations were found between PKCalpha protein and WA% or PI (P<0.01). Correlations between cyclin D1 protein and WA% or PI also existed (P<0.01). The expression of PKCalpha was positively correlated with the expression of cyclin D1 at both protein and mRNA levels (P<0.01). In conclusion, increased expressions of PKCalpha and cyclin D1 might be involved in the pathogenesis of abnormal proliferation of PASMCs in smokers with normal lung function and smokers with mild to moderate COPD.

The study on the Expression of Estrogen Receptors in Mast Cells of Bronchial Mucosa from Asthmatic Patients / 中国医师杂志

Objective To investigate the changes of estrogen receptor expression in mast cells of bronchial mucosa from female asthmatic patients.Methods 12 cases of female asthmatic patients and 9 cases of control female patients were enrolled in this study.The bronchial mucosa was obtained from the third grade bronchial by fiexible bronchofiberscope.Mast cells were marked by anti-mast cell tryptase monoclonal antibody,the expression of estrogen receptor(ER)were detected by anti-human estrogen receptor(ER)monoclonal antibodies.Results Mast cells and estrogen receptor positive cells of bronchial mucosa in female asthmatic patients were significantly higher than that in control group(P＜0.01).Coincident with the known features of bronchial asthma,the cells positive for estrogen receptor were morphologically similar to the mast cells.The cells stained for estrogen receptors by dual immunostaining coincided exactly with cells labeled as mast cells.Conclusion The result suggested the estrogen may be involved in the pathogenesis of female asthmatic patient through the changes of estrogen receptor expression in mast cells of bronchial mucosa.

The effects of protein kinase C (PKC) on the tension of normal and passively sensitized human airway smooth muscle and the activity of voltage-dependent delayed rectifier potassium channel (Kv) / 华中科技大学学报（医学）（英德文版）

The effects of protein kinase C (PKC) on the tension and the activity of voltage-dependent delayed rectifier potassium channel (K(y)) were examined in normal and passively sensitized human airway smooth muscle (HASM), by measuring tones and whole-cell patch clamp techniques, and the K(v) activities and membrane potential (E (m)) were also detected. The results showed that phorbol 12-myristate 13-acetate (PMA), a PKC activator, caused a concentration-dependent constriction in normal HASM rings. The constriction of the passively sensitized muscle in asthma serum group was significantly higher than that of the normal group (P<0.05), and the constrictions of both groups were completely abolished by PKC inhibitor Ro31-8220 and calcium channel inhibitor nifedipine. K(v) activities of HASM cells were significantly inhibited by PMA, and the E (m) became more positive, as compared with the DMSO (a PMA menstruum)-treated group (P<0.01). This effect could be blocked by Ro31-8220 (P<0.01). It was concluded that activation of PKC could increase the tones of HASM, which might be related to the reduced K(v) activity. In passively sensitized HASM rings, this effect was more notable.

The Effects of Protein Kinase C (PKC) on the Tension of Normal and Passively Sensitized Human Airway Smooth Muscle and the Activity of Voltage-dependent Delayed Rectifier Potassium Channel (Kv) / 华中科技大学学报（医学）（英德文版）

The effects of protein kinase C (PKC) on the tension and the activity of voltage-dependent delayed rectifier potassium channel (Kv) were examined in normal and passively sensitized human airway smooth muscle (HASM), by measuring tones and whole-cell patch clamp techniques, and the Kv activities and membrane potential (Em) were also detected. The results showed that phorbol 12-myristate 13-acetate (PMA), a PKC activator, caused a concentration-dependent constriction in normal HASM rings. The constriction of the passively sensitized muscle in asthma serum group was significantly higher than that of the normal group (P＜0.05), and the constrictions of both groups were completely abolished by PKC inhibitor Ro31-8220 and calcium channel inhibitor nifedipine. Kv activities of HASM cells were significantly inhibited by PMA, and the Em became more positive, as compared with the DMSO (a PMA menstruum)-treated group (P＜0.01). This effect could be blocked by Ro31-8220 (P＜0.01). It was concluded that activation of PKC could increase the tones of HASM, which might be related to the reduced Kv activity. In passively sensitized HASM rings, this effect was more notable.

Regulation of Cell Proliferation and Apoptosis by ERK Signaling Pathway in Airway Smooth Muscle Cells of Rats / 中国生物化学与分子生物学报

The regulative role of extracellular signal-regulated kinase(ERK)signaling pathway on proliferation and apoptosis in rats' airway smooth muscle cells(ASMCs)was investigated.Primary cultures of ASMCs were established and cells between passages 4 and 7 were used for experiments.ASMCs were U-eated with ERK activator epidermal growth factor(EGF)and inhibitor PD98059.The expressions of ERK mRNA and protein were detected by RT-PCR and immunofluorescence staining.Proliferation of ASMCs were detected by MTT eolorimetric assay and [3H] thymidine incorporation.Apoptosis of ASMCs were detected by Hoechst staining and Annexin-V FITC PI donble staining.The levels of ERK1/2,phosphorylated forms of ERK1/2(p-ERK1/2) and proeaspase-3 protein were detected by Western blotting.The expressions of ERK mRNA and ERK protein were obviously observed in ASMCs. Compared with control,the absorbanee(A490) value and DNA synthesis index of PD-treated ASMCs were significantly decreased(P＜0.05).The apoptotic index and the percentage of the early apoptotic cells were significantly increased(P＜0.05).The expressions of ERK1/2 and pERK1/2 protein were significantly down-regulated.The expressions of procaspase-3 protein was significantly increased.Compared with c,ontrol,the A490 value and DNA synthesis index were significantly increased(P＜0.05)in EGF-treated cells.Apoptotic index and the percentage of the early apoptotic cells were significantly decreased(P＜0.05).The levels of ERK1/2 and pERK1/2 protein were significantly increased,and the levels of procaspase-3 protein were significantly decreased, There were no significant differences between control and P+E group(P＞0.05).ERK signaling pathway may play an important role in regulating ASMCs proliferation and apoptosis and ERK regulating the apoptosis of ASMCs possibly relates to the expressions of procaspase-3 protein. The finding will help to understand the mechanisms of asthmatic ASMCs involved in abnormal proliferation.

Expression of Heme Oxygenase-1 in the Peripheral Blood Mononuclear Cells from Asthmatic Patients / 华中科技大学学报（医学）（英德文版）

To explore the expression of heme oxygenase-1 (HO-1) in the peripheral blood mononuclear cells (PBMCs) and its relationship with pulmonary ventilation function in asthmatic patients, 18 asthmatic patients and 18 healthy subjects were selected. HO-1 protein and mRNA levels in PBMCs were measured by immunohistochemical staining and reverse transcription-polymerase chain reaction (RT-PCR), respectively. Blood carbon monoxide Hb (COHb), serum total IgE and pulmonary ventilatory function were observed. Our results showed that the percentage of cells positive for immunohistochemical staining of HO-1 were significantly higher in asthmatic patients (41.72±7.44) % than that in with healthy subjects (10.45±4.36) % (P<0.001) and the optical density of PBMC HO-1 mRNA was higher in asthmatic patients (26.05±4.14) than that in healthy subjects (10.82±4.26) (P<0.001). The relation analysis showed that PBMC HO-1 protein and mRNA levels had significantly negative relation with FEV1 %, PEFR, MEFR50 %, respectively (r=-0.51-0.89, P<0.05-0.001, respectively) and a positive relation with COHb and serum total IgE (r=0.48-0.85, 0.05-0.001, respectively). It is concluded that the expression of PBMC HO-1 protein and mRNA increased significantly in asthmatic patients, and HO-1 may play a significant role in the pathogenesis of asthma. The expression of HO-1 may bear a relation with severity of asthma.

Changes in delayed rectifier K+ channel function and its regulation by protein kinase C pathway in bronchial myocytes from asthmatic rats / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate changes in the delayed rectifier K+ channel (Kv) function and the regulation of Kv by the protein kinase C (PKC) pathway in bronchial myocytes from asthmatic rats.</p><p><b>METHODS</b>The Kv currents and membrane potentials in bronchial myocytes from asthmatic rats and from controls were observed, using whole cell voltage- and current-patch clamp techniques.</p><p><b>RESULTS</b>Bronchial myocytes from asthmatic rats showed a significant reduction in Kv-current density (51.6 +/- 9.4 pA/pF, n = 14, P < 0.01) in comparison with those from control rats (72.4 +/- 12.3 pA/pF, n = 14) at + 50 mV. The current-voltage relationship curve exhibited a significant downward shift. Bronchial myocytes from asthmatic rats had no significantly different capacitances (P > 0.05), but had more positive membrane potential (P < 0.01) compared with those from controls. 1 micro mol/L phorbol 12-myristate 13-acetate, a PKC activator, caused an obvious reduction in Kv-current density (P < 0.01) and a significant downward shift in the current-voltage relationship curve, an effect which was partly abolished by 1 micro mol/L Ro31-8220 (a PKC inhibitor); 1 micro mol/L phorbol 12-myristate 13-acetate caused more positive membrane potential (Em), from -36.8 +/- 5.7 mV to -30.4 +/- 7.3 mV, in rat bronchial myocytes (P < 0.05). This effect was partly abolished by 1 micro mol/L Ro31-8220.</p><p><b>CONCLUSIONS</b>Bronchial myocytes from asthmatic rats have inhibited Kv function, more positive membrane potential, and higher excitability, all of which can also be induced by PKC activation. These characteristics may contribute to the development of airway hyperreactivity in asthma.</p>

K+ channels and their effects on membrane potential in rat bronchial smooth muscle cells / 华中科技大学学报（医学）（英德文版）

In order to investigate the K+ channels and their effects on resting membrane potential (Em) and excitability in rat bronchial smooth muscle cells (BSMCs), the components of outward K+ channel currents and the effects of K+ channels on Em and tension in rat bronchial smooth muscle were observed by using standard whole-cell recording of patch clamp and isometric tension recording techniques. The results showed that under resting conditions, total outward K+ channel currents in freshly isolated BSMCs were unaffected by ATP-sensitive K+ channel blocker. There were two types of K+ currents: voltage-dependent delayed rectifier K+ channel (Kv) and large conductance calcium-activated K+ channel (BKCa) currents. 1 mmol/L 4-aminopyridine (4-AP, an inhibitor of Kv) caused a significant depolarization (from -8.7 +/- 5.9 mV to -25.4 +/- 3.1 mV, n = 18, P < 0.001). In contrast, 1 mmol/L tetraethylammonium (TEA, an inhibitor of BKca) had no significant effect on Em (from -37.6 +/- 4.8 mV to -36.8 +/- 4.1 mV, n = 12, P > 0.05). 4-AP caused a concentration-dependent contraction in resting bronchial strips. TEA had no effect on resting tension, but application of 5 mmol/L TEA resulted in a left shift with bigger pD2 (the negative logarithm of the drug concentration causing 50% of maximal effect) (from 6.27 +/- 0.38 to 6.89 +/- 0.54, n = 10, P < 0.05) in the concentration-effect curve of endothine-1, and a right shift with smaller pD2 (from 8.10 +/- 0.23 to 7.69 +/- 0.08, n = 10, P < 0.05) in the concentration-effect curve of isoprenaline. It was suggested that in rat BSMCs there may be two types of K+ channels, Kv and BKca, which serve distinct roles. Kv participates in the control of resting Em and tension. BKca is involved in the regulation of relaxation or contraction associated with excitation.

Effect of nitric oxide on potassium channels of rat airway smooth muscle cells / 华中科技大学学报（医学）（英德文版）

The effect of nitric oxide donor sodium nitroprusside (SNP) on resting membrane potential (Em) and potassium currents of the bronchial smooth muscle cells from rats was investigated. All experiments were conducted in conventional whole-cell configuration. The changes of Em and potassium currents after addition of 0.1 mmol/L SNP were measured under the current-clamp mode and the voltage-clamp mode respectively. Results showed that (1) SNP could decrease the Em from -33.8 +/- 7.4 mV to -43.7 +/- 6.7 mV (n = 10, P < 0.01); (2) SNP could increase the Ca(2+)-activated K+ channel peak currents under ramp protocol from 466.9 +/- 180.1 pA to 597.7 +/- 237.6 pA (n = 7, P < 0.01), and the currents under pulse protocol at mV were increased from 544.2 +/- 145.4 pA to 678.1 +/- 206.2 pA (n = 6, P < 0.05); (3) SNP also could increase voltage-gated K+ channel peak currents under ramp protocol from 389.6 +/- 84.1 pA to 526.7 +/- 98.7 pA (n = 7, P < 0.01), the currents under pulse protocol at mV were increased from 275.7 +/- 85.2 pA to 444.3 +/- 128.5 pA (n = 6, P < 0.01). It was concluded that SNP increases the activities of Ca(2+)-activated K+ channels and voltage-gated K+ channels and leads to K+ efflux and hyperpolarization of the cell membrane, resulting in a decrease of the cell excitement.

Effects of endogenous nitric oxide on potassium channels of bronchial smooth muscle cells from asthmatic rats / 中国病理生理杂志

AIM: To investigate the effects of in vivo application of L - arginine on potassium channels in bronchial smooth muscle cells (BSMC) isolated from asthmatic model rats.METHODS: Male SD rats were randomly divided into control group,asdimatic group and asthmatic rats treated with L-arginine (L-Arg group). Single BSMCs were obtained by acute enzyme separation method. The resting membrane potential (Em), Ca2+ - activated K+ channels (BKca) currents and voltage - dependent K+ channel (Kv) currents in BSMCs were recorded under whole - cell patch clamp technique. RESULTS: (1) The Em of asthmatic group was significantly lower than that in control group ( P 0.05) . (2) The peak current density at + 50 mV of Kca: IKca in asthmatic group [ (43.8?16.5) pA/pF] was significandy lower than that in normal group [ (72.5?19.9) pA/pF] ( P

Effect of nuclear factor kappa B on TNF-? induced proliferation,apoptosis and the expression of TGF-?_1 in airway smooth muscle cells / 中国病理生理杂志

AIM:To investigate the effect of nuclear factor kappa B(NF-?B)on proliferation,apoptosis and the expression of TGF-?1 in airway smooth muscle cells(ASMCs).METHODS:Cultured ASMCs were divided into three groups and stimulated with or without TNF-? and pyrrolidine dithiocarbamate(PDTC)in vitro.Reverse transcriptase-polymerase chain reaction(RT-PCR)was used to detect the expression of TGF-?1 mRNA.The location and protein expression of PCNA and Bcl-2 were observed by immunocytochemical staining.The protein expression of TGF-?1 and NF-?B was detected by Western blotting.The proliferation and apoptosis of ASMCs were also observed.RESULTS:The activity of NF-?B in TNF-? group was significantly higher than that in control group and TNF-? plus PDTC group,respectively(P

Activity of delayed rectifier potassium channel in alveolar macrophages from COPD rats / 中国病理生理杂志

AIM: To explore the change of delayed rectifier potassium channel (K_V) activity in alveolar macrophages (AM) in chronic obstructive pulmonary disease (COPD) rats. METHODS: COPD model was established by exposure of the animals to cigarette smoke. With whole-cell voltage- or current-clamp techniques, K_V activity, membrane capacitance and resting membrane potential (Em) in AM from COPD model and control rats were compared. RESULTS: (1) Significant increases in total mononuclear cells and AM in bronchoal aveolar lavage fluid (BALF) were found in COPD group compared with in control group. (2) The AM K_V current altitude in COPD group [(520.5?38.7)pA, (+50) mV, n=30] was significantly lower than that in control group [(713.6?44.4)pA, (+50) mV, n=30, P0.05), but had more positive Em (P

Effect of liposome-mediated transfection of Kv1.5 antisense oligonucleotides on activity of Kv in airway smooth muscle cells / 中国病理生理杂志

AIM:To investigate the activity change of voltage-dependent delayed rectifier potassium channel(Kv) on human airway smooth muscle cells(HASMCs) after transfection of Kv1.5 antisense oligonucleotides(AsOND),and to discuss the regulating mechanism of Kv1.5.METHODS: The mRNA and protein expressions of Kv1.5 in liposome-mediated Kv1.5 AsOND transfected HASMCs were measured with techniques of reverse transcriptase-polymerase chain reaction(RT-PCR) and Western blotting.Kv activities in transfected HASMCs were investigated with whole-cell patch clamp.RESULTS: After HASMC were transfected by liposome-mediated Kv1.5 AsOND,the mRNA and protein expressions of Kv1.5 were decreased,and Kv activity was inhibited,which made the cell membrane potential(Em) inclined to depolarization.CONCLUSION: Transfection of Kv1.5 AsOND made the function of Kv in HASMCs decreased.Kv1.5 may play a critical role in the regulation of Kv activity.