Morphological changes positive correlates with oxidative stress in COPD. Preliminary data of an experimental rat model--study and literature review.

It is well known that nicotine that is a major toxic component of cigarette smoke induces oxidative stress which is responsible for the lung damages in COPD and cancer. There have been reported some cases of COPD in never smoking patients exposed to air pollutants. The aim of our study is to evaluate the morphological pulmonary changes in rats exposed to cigarette smoke respectively to solid combustible smoke and to establish the relationship between the exposure and the level of oxidative stress measured through serum (s) and pulmonary tissue (l) MDA in rats (TBARS method). Thirty Wistar rats were divided into three groups (n = 10): (1) the control group (C), (2) the cigarette smoke group (CS), and (3) the solid combustible smoke group (SC). Apart from the control group, these were treated with solid combustibles smoke or cigarette smoke for six months. We collected blood for serum determination of MDA and the lungs were removed for histopathological analysis and to determine the levels of malondialdehyde (MDA). The levels of serum and lung MDA were significantly higher in CS and SC groups compared with C group, but not significantly differences between CS and SC group were detected. These findings are positively correlated with histopathological changes (squamous metaplasia and clear cell hyperplasia in the bronchium epithelium, emphysema) found in pulmonary tissue. Preliminary data of our study confirms that not only the cigarette smoke but also the environmental pollutants are involved in the major pathways of COPD.