Imaging SHS Deposition in the Airways of Sprague-Dawley Rats

TRDRP and other funding agencies support investigations into the health effects of cigarette smoke inhaled directly or from environmental exposure. Laboratory animals are inevitably used as models for exploring the health effects caused by inhaling cigarette smoke despite concerns that particles deposit in animal airways quite differently than in human ones. But animal models are crucial to understanding the health effects of tobacco smoke because in vivo studies can be performed in such models that are not viable in human subjects. Since the location of particle deposition determines subsequent clearance and transport to other tissues, mapping particle deposition throughout the airways in laboratory animals is crucial to understanding the health effects that they cause and their relationship to that in humans, but such mapping has yet to be performed because methods for measuring the particle locations are not available.

The long-term goal of the proposed research is to map the location of cigarette smoke particle deposition in the airways and disposition throughout the body. We have developed methods for reconstructing the airway tree from images, which will assist in this effort. We have also developed methods for imaging the location of particle deposition in laboratory animals, for particles that are fluorescently labeled. The goal of the current proposal is to map the location of Environmental Tobacco Smoke particles in airways of Sprague-Dawley rats. This mapping will assist a wide range of other investigators exploring the mechanisms whereby cigarette smoke harms respiratory health. It will also set the stage for subsequent studies of cigarette smoke particle transport to other organs and their subsequent health effects.