An Experimental Study Of The Protective Action On Alveolar Macrophages Of Pulmonary Emphysema By Bilirubin

Objective: To investigate the protective action of bilirubin on alveolar macrophage(AM) of pulmonary emphysema to explore a new method of prevention and cure of pulmonary emphysema. Methods:36 healthy Wister rats were divided into 3 groups at random: normal control group(12), pulmonary emphysema model group(12), bilirubin treated group(12).Rats in model group and treated group were exposed to cigarette smoke in a experimental device once a day, six days a week, six consecutive months. Rats in treated group were instilled bilirubin before exposed to smoke; rats in model group and control group were instilled the equal amount of physiological saline. All of the rats in three groups were sacrificed to be tested after six months. The levels of total bilirubin of serum, MDA of broncho-alveolar lavage fluid (BALF), MDA, interleukin(IL)-8, nitric oxide (NO) in cultural supernatant liquid of AM were determined.The expressions of nuclear factor kappa B(NF- B)mRNA and inducible nitric oxide synthase(iNOS) in AM, pathology were examined. Results: (1)Model group compare with control group: the levels of total bilirubin of serum were not decreased(P>0.05); the content of MDA,IL-8,NO were increased (P<0.05); the expressions of NF-BmRNA and iNOS in AM were increased(P<0.05). (2)Treated group compare with model group: the levels of total bilirubin of serum were increased(P<0.05); the content of MDA, IL-8, NO were decreased(P<0.05); the expressions of NF- K B and iNOS in AM were decreased(P<0.05). (3)The significant negative correlation results: between the levels of total bilirubin of serum and MDA(BALF), MDA (cultural supernatant liquid of AM), the expressions of NF- K BmRNA(respectively, r=-0.584, P<0.05; r=-0.406, P<0.05; r=-0.387, P<0.05). The significant positive correlation results: between the expressions of NF-BmRNA and the expressions of iNOS, the content of IL-8 and NO (respectively, r=0.927,P<0.05; r=0.722, P<0.05; r=0.731, P<0.05); between the expressions of iNOS and the content of NO(r=0.729,P<0.05). (4)In model group, the change of pathological observation were accorded with those of emphysema and the change of AMs were obvious; in treated group, the change of all were obviously lighten. Conclusion: (1)High expressions of NF-B, iNOS, IL-8 and NO relates to the forming of pulmonary emphysema. (2)Bilirubin exerts somewhat protection on AMs and inhibition on the process of pulmonary emphysema.