Objectives: This study was undertaken to investigate smoke-induced structural and biochemical changes and protective effects of co-administred of melatonin and vitamin C in rat trachea.

Materials and Methods: Twenty-four Wistar female rats were used. Animals were divided into four groups. The first group of rats used as control. The second group of rats were inhalated cigarette. Cigarette inhalated third and fourth group of rats recieved melatonin and vitamin C respectively. At the end of the study trachea tissues and blood samples were taken under the anesthesia. Tissues were prepared and examined by light microscopy. And biochemically, malondialdehyde and glutathione levels and catalase activities were determined.

Results: Microscopically, blood and desquamation of epithelial cells in the tracheal lumen, activated granular cells and apoptotic cells in the epithelial layer and activated serous gland in the submucosal layer were detected in the group II. In the group III and IV melatonin and vitamin C relatively protected the trachea tissue against smoke intoxication. Biochemical examination showed malondialdehyde levels in the group II higher than group I, melatonin and vitamin C injection to group III and IV caused to decrease of malondialdehyde. Glutathione levels and catalase activity in the group II were less than group I. Melatonin and vitamin C injection did not change the decrease of the glutathione levels and catalase activities in group III and IV.

Conclusion: As a result, cigarette inhalation increased lipid peroxidation and antioxidant system and caused structural changes. However, melatonin and vitamin C administration obtained relative protection against smoke.©2005, Fırat Üniversitesi, Tıp Fakültesi