Host: The Japanese Society of Toxicology
The conventional methods of inhalation exposure for cigarette smoking required expensive equipment and wasted labor to induce potential toxicity. Therefore, we attempted to develop a novel method using intratracheal instillation (ITI) of whole cigarette smoke condensates (WCSC). The WCSC was prepared as a 20 mg/mL and diluted to 10 and 5 mg/mL, and was administered by ITI using an automatic video instillator. Separated two experiments were performed; study 1= ITI, 12 times, 28 days (3 time/week), 4 groups (1, 2, 3, 4 weeks), study 2 = ITI, 12 times, 12 days (everyday), 2 groups (6, 12 days). After final ITI, the bronchoalveolar lavage fluid (BALF) and lung tissue were collected. The BALF was analyzed using commercially available sandwich ELISA method. A mild histopathological change was observed in lung tissues treated with WCSC (20 mg/mL) for 28 days. On the other hand, repeated ITI of WCSC for 6 days increased the body and lung weight, and the level of neutrophils and lymphocytes compared to the control. In addition, the histopathological markers were observed in the lung tissues treated with a high dose of WCSC. An analysis of BALF from 6- and 12-day groups confirmed the inflammatory changes and altered secretion of a related cytokine, MCP-1, were observed in this study. However, no significant changes in the secretion of CXCL-10 and IL-2 were detected. In summary, ITI exposure may be a more brief and effective method to evaluate the adverse effects of WCSC via a short period of exposure less than 2 weeks.
