Nasal diagrams: a tool for recording the distribution of nasal lesions in rats and mice.

Knowledge of patterns of lesion distribution can provide insight into the relative roles played by regional tissue dose and local tissue susceptibility in toxic responses to xenobiotics in the nose and assist assessment of potential human risk. A consistent approach is needed for recording lesion distribution patterns in the complex nasal airways of rats and mice. The present work provides a series of diagrams of the nasal passages of the Fischer-344 rat and B6C3F1 mouse, designed for mapping nasal lesions. The diagrams present each of the major cross-sectional airway profiles, provide adequate space for nasal mucosal lesion recording, and are suitable for duplication in a commercial photocopier. Sagittal diagrams are also provided to permit transfer of lesion location data observed in transverse sections onto the long axis of the nose. The distribution of lesions induced by a selected range of xenobiotics is presented. Approaches to application of the diagrams and interpretation of results obtained are discussed in relation to factors responsible for lesion distribution in the nose and their relevance to interspecies extrapolation. A modified approach to anatomical classification of the ethmoturbinates of the rodent is also presented.