The practice of structure activity relationships (SAR) in toxicology

Both qualitative and quantitative modeling methods relating chemical struct ure to biological activity, called structure-activity relationship analyses or SAR, are applied to the prediction and characterization of chemical tox icity. This minireview will discuss some generic issues and modeling approa ches that are tailored to problems in toxicology. Different approaches to, and some facets and limitations of the practice and science of, SAR as they pertain to current toxicology analyses, and the basic elements of SAR and SAR-model development and prediction systems are discussed. Other topics in clude application of 3-D SAR to understanding of the propensity of chemical s to cause endocrine disruption, and the use of models to analyze biologica l activity of metal ions in toxicology. An example of integration of knowle dge pertaining to mechanisms into an expert system for prediction of skin s ensitization to chemicals is also discussed. This minireview will consider the utility of modeling approaches as one component for better integration of physicochemical and biological properties into risk assessment, and also consider the potential for both environmental and human health effects of chemicals and their interactions.