Efeitos da inalação passiva da fumaça de cigarro sobre as pregas vocais de ratos

Abstract

Few studies have demonstrated the pathologic reactions yielded by smoke inhalation on the airway in rats. Aim: The aim of this study was to analyze the possible histopathological effects produced by chronic cigarette smoke inhalation on the vocal folds of rats. Study design: Experimental. Material and Method: 36 male rats (Rattus norvergicus Wistar strain), aged 60 days, were kept in cages and exposed to inhalation of the smoke produced by 10 cigarettes lit 3 times a day, 7 days a week, for periods of 25, 50 and 75 days, and their respective controls. Thereafter the animals were killed and their larynxes were dissected and submitted to histological processing for achievement of histological sections, which were stained with Hematoxylin and Eosin and analyzed by light microscopy. Results: The rats exposed to smoke displayed smaller (p< 0,05) body mass than the control group. There was hyperplasia and squamous metaplasia in the free edge of the vocal fold and squamous hyperplasia on the middle portion of the vocal fold in all 3 study periods. Moreover, the 50-day group revealed keratinizing metaplasia in this area. Morphological alterations in other areas of the larynx and inflammatory reaction of the lamina propria were also not observed. Conclusion: It was concluded that the passive inhalation of cigarette smoke yields important morphological changes in the vocal fold epithelium, which may progress to neoplasia.

Morphology of laryngeal cartilage of the nine‐banded armadillo (Dasypus novemcinctus) Linnaeus, 1758

“…The arytenoid cartilage in nine‐banded armadillos presented cylindrical pseudostratified epithelium, but in some animals as in rats (Duarte et al, ), the transition between stratified squamous epithelium and respiratory epithelium can be observed. The coatis, however, presented a tissue formed only by squamous stratified epithelium (Oliveira et al, ).…”

Effects of passive inhalation of cigarette smoke on structural and functional parameters in the respiratory system of guinea pigs

“…Such effects were proven by evidence of a deficit in lung tissue; an increase in inflammatory cells, leading to mucus accumulation; and pulmonary function impairment caused by tracheal hyperreactivity. Although some inhalation models 13 , 14 , 21 , 22 have reported the damages caused by constant and prolonged use of cigarettes, the relevance of the present study lies in reporting the changes caused by passive inhalation of cigarette smoke over a short period of time (5 days), with a change in the amount and duration of exposure to cigarette smoke as compared with previous studies. 23 - 25 In their study, Hernandez et al 23 also opted to analyze the effects of passive inhalation of cigarette smoke over a short period of time.…”

Effects of inhaled cigarette smoke on the myo-articular system of female rats with collagen-induced arthritis

“…The aspirated smoke was then injected into the box, which contained 3 animals 13. One cigarette was used per rat 10,11,14. The animals were exposed three times a day for 10 minutes (every 6 hours, beginning at 7:00 a.m. and with a 12-hour interval between treatments) for a consecutive period of 28 days 10,11,13,14.…”