Chapter 8: Target Organ and Target System Toxicity
The detection of specific target organ and target organ system toxicity is an important aspect of toxicological testing, and the conventional test procedures involve chronic, repeat-dose in vivo testing, often in a non-rodent species as well as in a rodent species. This kind of predictive testing represents an enormous challenge to those who, for a variety of scientific and ethical reasons, would like to see animal testing replaced by non-animal tests and testing strategies. It will be worthwhile putting considerable skill and effort into attempts to meet this challenge, not least because, as in the case of carcinogenicity testing (Chapter 9) and reproductive toxicity testing (Chapter 10), inter-species differences limit the usefulness of animal studies for predicting long-term target-organ and target-system effects in humans. It should also be borne in mind that strategies for assessing target organ and system toxicity need to take into account the biokinetic considerations of absorption, distribution, metabolism and excretion.