Interleukin-9 And Interferon-gamma Are Contributing To Airway Inflammation In Rat Model Of Chronic Obstructive Pulmonary Disease

Objective To investigate the changes of interleukin9(IL-9) and interferon-gamma(IFN-γ) in smoke-induced of chronic obstructive pulmonary disease(COPD) rat models.Methods Rat model of chronic obstructive pulmonary disease(COPD)was established by exposure Male Wistar rats to cigarette smoke daily for 75 days. Total cell counts and macrophages counts in BALF were examined. The level of IL-9 and IFN- Y in serum or BALF and lung tissue were measured with ELISA. Lung tissues section stained by HE was observed to study the morphological alternations and Lm and MAN were measured.Result (1) Lm in COPD group were higher than those in control group (P<0. 01) while MAN was decreased on the contrary. (2)Statistic analysis showed that level of IL-9 in serum or BALF and lung tissues of COPD group were higher than those ofcontrol group[ (4.02 + 2. 12pg/ml) VS (1. 12 + 0. 73 pg/ml), P<0. 01], [ (5.73 + 2.60 pg/ml) VS (0.97 + 0.45 pg/ml) ,P<0.01]> [ (24.92 +6.65 pg/ml) VS (11.42+4.23 pg/ml) ,P<0. 01], while that level of IFN-y in serum and in lung tissues were lower than those of control group[ (21. 54+7. 65)VS[ (69. 59 + 13. 68 pg/ml), P<0. 01] > [(21.88+6.11 pg/ml)VS (69.84 + 15.35 pg/ml), P<0.01]. (3)In the BALF of COPD group, total cell counts was (5. 29 + 1. 61) 108/L , macrophages counts was (4. 42 + 1. 38) X10 /L, while in the BALF of control group , they were (2.10 + 1.19) X108/L, (1.84+0.93) Xo10 /L, respectively. There were significances differences in these indexes between the smoke exposed group and the control group (P<0.01). (4) Positive correlations were demonstrated between the level of IL-9 in BALF or in Lung tissue and macrophages counts in BALF in COPD group (P<0.01 or P<0. 05), but not the level of IL-9 in serum. And there were negtive correlations between the level of IL-9 and IFN- y in Lung tissue.Conlusions ( 1 ) COPD rat model were successfully established by passive cigarette smoking;Cigarette smoke exposure increased IL~9 and decreased IFN- y, this may play a role in smoke-induced emphysema. (2)Our data implied a close correlation between IL-9 in BALF and airway inflammation in COPDrat model. IL-9 may be used a diagnostic marker in airway-inflammation of COPD. (3) IL-9 play a role in COPD partly by restraining IFN-Y.