Effects Of Smoking On The Expressional Levels Of 5-lipoxygenase Protein And MRNA In Sensitized Rats Airway And The Intervention Of Zileuton

Objective To study the effect of smoking on airway inflammation of asthma and put forward experimental basis for the treatment of asthma of smoking through researching the effect of smoking on the expressional levels of 5-lipoxygenase protein and mRNA in sensitized rats airway.Methods Forty healthy male wistar rats were divided randomly into control group, sensitized group,smoking sensitized group,zileution sensitized group and zileution smoking sensitized group. The rats of latter four groups were sensitized with the ovalbumin 1ml,aluminum hydroxide powder 100mg injected intraperitoneally ite first day and eighth day and challenged by inhaling 1% ovalbumin 60ml placed in transparent airtight container to establish the asthmatic model,once every day,40 minutes on,10 week in total. From the challenged third weeks, the smoking sensitized group and zileution smoking sensitized group rats were put in the self-made fumigating box to smoke passively,one time every day, ten cigarettes every time, six day one week and eight weeks in all,the smoking room size is 60 cm×50 cm×40 cm. From the challenged third weeks,The rats of last two groups were fed zileution 30min before each challenging,35mg/kg. the control group gave saline instead of ovalbumin,the other remaining conditions is kept the same.In 24 hours after last inhalation,the rats were killed,complete free the heart and lung tissue, the lung tissue was embedded in paraffin and sliced.The expressions of 5-lipoxygenase protein and mRNA in airway were defected using immunohistochemistry and hybridization in situ in all rats of five groups.Results①The expression of airway 5-lipoxygenase protein of smoking sensitized group (32.58±2.78) were significantly higher than those of the sensitized group(21.65±2.12) and the control group(12.38±1.68;all P<0.01),so did the sensitized group and the control group, (P＜0.01);zileution sensitized group (15.32±1.58) were lower than those of the sensitized group(P<0.05); zileution smoking sensitized group (16.20±2.38) were lower than those of the smoking sensitized group (P<0.01);②The expression of airway 5-lipoxygenase mRNA of smoking sensitized group (34.68±2.90) were significantly higher than those of the sensitized group(23.55±2.28) and the control group(12.78±1.72; all P<0.01),so did the sensitized group and the control group (P＜0.01); zileution sensitized group (16.38±1.26) were lower than those of the sensitized group(P<0.01);zileution smoking sensitized group (17.18±2.26) were lower than those of the smoking sensitized group (P<0.01).Conclusion Smoking can increase the expession level of 5-lipoxygenase protein and mRNA in sensitized rats airway and aggravation airway inflammation,zileution can reduce airway inflammation by reduce the expession level of 5-lipoxygenase protein and mRNA.Combined use of effective anti-LTs drugs may increase the efficacy in patients of smoking asthma in clinical.