PHARMACOLOGY/TOXICOLOGY
After in vitro experiments, new compounds need to be administered to living animals. Pharmacology and toxicology data show whether a potential drug has toxic side effects and its safety at different doses. Animal testing measures how much of a drug is absorbed into the blood, how it is broken down chemically in the body, the toxicity of its breakdown products (metabolites), and how quickly the drug and its metabolites are excreted from the body. Venous blood is collected for pharmacokinetic data, for monitoring immunologic responses, for complete blood counts and for chemistry analysis. A complete necropsy is performed on each animal and major organs are collected for histopathology review. Pathology is performed by a board-certified animal pathologist.
Mice and rats are generally the species of first choice because their mammalian bodies are incredibly similar to those of humans and usually provide a good basis for predicting how a new compound will react inside the body. Other species are used in studies only if sufficiently meaningful results are unlikely to be obtained using rats and mice. In safety studies, the FDA usually demands studies in a non-rodent species (pigs, non-human primates) as well as rodents to ensure that possible effects or side effects are detected before the product is used in humans for the first time. At the Institute, the non-rodent species of choice is Cynomolgus macaque because of their genetic, anatomical and immunologic similarities to humans.