RESUMEN
Adult male rats were exposed to cigarette smoke [2x/day/6 wks] in locally prepared chamber with an objective to study the effect of daily smoke exposure on body weight gain and possible epithelial changes encountered in the respiratory air-ways in conjunction with oral intake of 300 IU [2x/wK/6wK] of retinol palmitate. The exposure to cigarette smoke caused a significant [P<0.01] decrease in body weight gain relative to sham exposed animals, while the oral retionl intake had improved the gain over sham-treated. Analysis of serum retinol levels revealed a significant [P<0.001] decrease in the smoke-exposed rats relative to sham exposed rats. The epithelial changes of the larynx were the most prominent changes of the respiratory airways which varied from pseudostratified columnar ciliated epithelia to squamous metaplasia in the smoke-exposed rats while in those supplemented with the retinol, the laryngeal epithelia was nearly that of the sham-exposed and there was no sign of squamous metaplasia. Apparently, the retinol supplementation during cigarette smoke exposure might had a prophylactic role in human against unwanted cellular changes of the respiratory airways