Stress and hypothermia in Mice in a Nose-Only Cigarette Smoke Exposure System

Introduction:
This text presents the results of a study investigating the effects of restraint and cigarette smoke exposure on body temperature and stress parameters in mice using a nose-only exposure system. The study found that restraint in the exposure tubes led to a substantial and proportional decrease in body temperature, while smoke exposure caused a dose-dependent further decrease in body temperature. additionally, the study found that repeated restraint in the exposure tubes resulted in chronic stress in the mice.

Key Points:

* The study used C57Bl/6J male mice and exposed them to cigarette smoke in a nose-only exposure system.
* Restraint in the exposure tubes led to a decrease in body temperature, while preheating the nosepieces prevented this.
* Smoke exposure caused a dose-dependent further decrease in body temperature.
* Prolonged exposure to smoke or room air in tubes with heated nosepieces resulted in minor decreases in body temperature.
* Restraint, but not smoke exposure or hypothermia, reduced body weight gain and increased relative adrenal weights.
* The study suggests that repeated restraint of mice in exposure tubes is a major cause of chronic stress.
* Decapitation would have been a better method to terminate the animals to observe an increase in plasma corticosterone levels.

Main Message:
The study found that restraint in nose-only exposure tubes led to a significant decrease in body temperature in mice, while smoke exposure caused a further decrease in body temperature. additionally, the study found that repeated restraint in the exposure tubes caused chronic stress in the mice, indicating that this could be a confounding factor in long-term nose-only exposure studies. The study highlights the importance of considering the effects of restraint and stress in inhalation toxicology studies using nose-only exposure systems.

Van Eijl, S., R. Van Oorschot, B. Olivier, F. P. Nijkamp, and N. Bloksma. “Stress and hypothermia in Mice in a Nose-Only Cigarette Smoke Exposure System.” Inhalation Toxicology 18, no. 11 (January 2006): 911–18. https://doi.org/10.1080/08958370600822672.