Expression of Gq in bronchopulmonary tissues in rats after inhalation of cigarette smoke / 第三军医大学学报

ABSTRACT

Objective To study the expression of Gq protein in bronchopulmonary tissues of rats of chronic obstructive pulmonary disease (COPD) model and the roles of inflammation in airway of COPD rats. Methods A total of 44 Wistar rats were divided randomly into 4 groups nonsmoking control group, 1 month smoking group, 2 month smoking group, and intervention group (dexamethasone + smoking for 2 months). The pathological changes of lung tissues and the total and differential count of white blood cells in bronchoalveolar lavage fluid (BALF) in all groups were observed. The expression of Gq in bronchopulmonary tissues was detected by immunohistochemical method and Western blot analysis. Results More significant increases in total number of leukocytes and neutrophils in BALF were found in the model group than those in the control group. Gq was mainly expressed in airway epithelial cells, inflammatory cells, and pulmonary capillary endothelia. Weak expression of Gq was found in bronchopulmonary tissues in the control group, but overexpression of Gq in the model group. The ratios of Gq positive cells in bronchopulmonary tissues were significantly correlated with the number of white blood cells and neutrophils in BALF. The levels of expression of Gq were significantly higher in the model groups and intervention group than those in the control group. More significant decrease in Gq expression was found in the intervention group as compared with that in 3 month smoking group. Conclusion Gq may be involved in the process of airway inflammation in COPD. Inhibition of the Gq overexpression might be a new approach to the treatment of COPD. Corticosteroid might have some effects on the inhibition of the airway inflammation.