The Research Of Cold-sensitive Channel Activity By Cold Air Stimulation Effect On Inflammation In Rat Lungs

Part 1 The Research of cold-sensitive channel activity by cold air stimulation effect on inflammation in rat lungsObjective:To investigate the effect of rapid repeated cold air inhalation stimulation on cold-sensitive channel TRPA1 associated inflammatory cytokines in the living lung.And the effects of repeated cold air inhalation on the distribution of inflammatory cells and infiltration in the lungs tissue of animals.To clarify the mechanism of repeated cold air inhalation in asthma.Methods:A total of 20 male Wistar rats were randomly divided into 4 groups with 5 animals in each group.Cold air inhalation group,warm air inhalation group,TRPA1 channel agonist inhalation group and the normal group,respectively.Tracheal intubation was carried out after anesthesia in rats of cold air inhalation group,and the tubes were linked to the air temperature controlled device.The temperature was controlled at(2±1)℃.The rats of warm air inhalation group were treated in the same way as cold air inhalation group except the temperature keeping at(36±1)℃.The rats of both groups were treated for 3 times,1 hour each time.There were 12 hour intervals between twice treatments.The rats of TRPA1 channel agonist inhalation group were treated with atomizing inhalation of 60 m M acrolein at room temperature(24±2)℃ for 3 times,1 hour each time.There were 12 hour intervals between twice treatments.The rats were killed after the last treatment.HE staining was performed in the trachea and right lung tissue of the normal group,had been used cold air inhalation group and TRPA1 channel agonist inhalation group,to examine the pathological changes of the trachea and lung.The tracheas and left lung tissues of all rats were taken and the total RNA was extracted.The m RNA expressions of TRPA1,interleukin 1 beta(IL-1β),interleukin 5(IL-5),neutrophil chemoattractant chemokine(CXCL-1/KC)in the rat lungs were detected by real-time quantitative PCR.Results:Microscopically trachea and lung tissue structure of normal control rats were normal and infiltration of inflammatory cells was not found.But,in the cold air inhalation group and TRPA1 channel agonist inhalation group,we could find the airway mucosa was obviously infiltrated by inflammatory cell,bronchial mucosa edema,lumen and alveolar interstitial thickening,even,alveolar significantly was infiltrated by inflammatory cells in rats trachea and lung tissue under a microscope.TRPA1 m RNA was expressed in rat lung tissues using PCR.In the short term cold air inhalation group,the expressions of IL-1β、IL-5、CXCL-1/KC m RNA in the rats lung were higher than those of the warm air inhalation or the normal groups(P<0.05).Similar results were also found in the specific TRPA1 channel positive agonist(acrolein)inhalation group.Conclusions:In animals,the TRPA1 channels of the lungs can be activated at short-term cold air(<17℃),which results in the increasing expression of some inflammatory cytokines,a lot of inflammatory cells aggregated and infiltrated in the lung.It is suggested that the inhalation of cold air can induce asthma.Part 2 Analysis of 26 new cases of asthma soldiers in frigid climatic areaObjective:To further understand the risk factors of inducing bronchial asthma in combating and training soldiers in frigid climatic areas and explore the protection strategy of bronchial asthma.Methods:26 soldiers within two year after joined army,who were newly diagnosed as bronchial asthma,were selected as investigation object,out of 15035 soldiers enlisted into Shenyang Military Command in 2012 who were survey subjects of epidemiology investigation of Department of Respiration and Critical Care medicine,General Hospital of Shenyang Command.Common induced factors of asthma were investigated by the questionnaire survey way.Results:In 26 soldiers with new cases of asthma,cold air contact was the most common attack causes besides respiratory tract infection,accounted for 65.4%.More than 80% of soldiers with new onset asthma had the long-term training experience in the cold environment(more than 3 months per year).About episodes of season,more than 50% of cases(14 cases)had the first time asthma symptoms in winter and 19 out of 26 cases with asthma appeared in winter,accounted for 73.1% and 10 cases occured in Spring Festival,accounted for 38.5%.These data showed an obvious seasonal characteristic,that is,winter is more likely to induce or aggravate asthma.Allergic rhinitis is main accompanying diseases of asthma patients(42.3%).Conclusions:Cold air contact is one of the main induced factors of asthma in soldiers of frigid climatic area and winter is the season of high incidence of asthma.