Morphometric evaluation of inhaled particles in sections of the lung

Traditionally, pulmonary toxicity has been evaluated by conventional histology. Quantitation, however, offers a number of advantages. It provides a more rigorous comparison of the effects of drugs at different concentrations and demonstrates changes that are individually too small to be detected by qualitative means but collectively may have considerable effects. Some authors describe methods for stereological evaluation of histological parameters of the lung. All these methods are time-consuming, since many manual interventions are required at each step of the process. In addition the sampling strategy must take into account where changes are likely to occur. Differences might be anticipated between left and right lung, lobes and upper or lower regions. Within the gross anatomical units, changes might be localised within parenchyma, airways or vasculature. (Abstract truncated.)