Low Doses of Kretek Cigarette Smoke Altered Rat Lung Histometric, and Overexpression of the p53 Gene

The components of kretek cigarettes include tobacco as the main part, clove, and sauce. Filtered kretek cigarettes are kretek cigarettes that have one end filtered. Cigarette smoke contributes to the disruption of the respiratory system, so it is necessary to know the effect of low doses of cigarette smoke on changes in the histometric of the respiratory system, and whether it affects p53 gene expression. This study aims to determine changes in the histometric of the respiratory system and p53 gene expression.

In this study, we used Sprague-Dawley rats. Group I of rats breathing normal air, were not exposed to filtered kretek cigarette smoke (as a control). Group II of rats, as a treatment group, were exposed to filtered kretek cigarette smoke 1 stick/day for 3 months. The results of lung histometry measurements and p53 gene expression between groups were analyzed using the Independent Sample T-test. The difference between groups is significant if the test results show P < 0.05.

Bronchioles length, width, area, and perimeter in group I were 40.55±1.57 μm, 14.82±0.41 μm, 494.61±5.62 μm², and 233.87±4.51 μm, respectively. Bronchioles length, width, area, and perimeter in group II were 30.76±0.78 μm, 9.28±0.40 μm, 297.32±2.53 μm², and 177.84±5.15 μm, respectively. The area and perimeter of respiratory bronchioles in group I were 17.68±0.49 μm², and 26.60±0.52 μm respectively, while those in group II were 19.28±0.35 μm², and 29.28±0.35 μm, respectively. Mucus was found in the bronchioles and respiratory bronchioles in group II, however, there was no visible mucus observed in group I. In addition, it was also concluded that exposure to low doses of filtered kretek cigarette smoke, 1 cigarette/day for 3 months, increased the expression of the p53 gene in the lungs of rats.

The size of bronchioles in rats decreased after being exposed to filtered kretek cigarette smoke 1 stick/day for 3 months, while the size of respiratory bronchioles increased. In addition, exposure to filtered kretek cigarette smoke increased the expression of the p53 gene in the rat lungs.