Clinical Chemistry in Toxicity Testing: Scope and Methods

Noncellular blood compartment (plasma or serum) and urine biochemical components are important indicators of overall animal health and can be used in conjunction with other parameters to investigate the toxicity of drugs and chemicals. This chapter describes the measurement and interpretation of clinical chemistry tests employed in toxicology studies in commonly used laboratory species. The introductory sections delineate methods for sample collection and data generation, and provide a general approach for data interpretation and reporting, with emphasis on distinguishing pre-analytical/analytical variations from test material-related changes. The following sections are organized by organ system, describing core clinical chemistry tests used in routine toxicology studies. These include protein, lipid and carbohydrate metabolisms, liver and kidney functions and electrolyte balance. Nonroutine tests evaluating cardiac and skeletal muscle, bone, blood vessels, the endocrine system, the nervous system are also presented. Because few clinical chemistry parameters are specific indicators of single organ toxicity, each section emphasizes the integrated interpretation of biochemistry changes with other study endpoints such as clinical signs, food consumption and bodyweight, haematology, electrocardiography, blood pressure and histopathology. Patterns of change are presented in the context of identifying organ toxicity. Keywords: clinical chemistry; serum; plasma; urine; kidney; liver; cardiac muscle; skeletal muscle; bone; blood vessel; adrenal; gonads; ovary; thyroid; GI tract; pancreas; nervous system