Adrenal Gland Background Pathology of Primates in Toxicological Studies Joachim Kaspareit
Nonhuman primates represent unique animal models for human diseases because of their phylogenetic relationship to man. Especially, the cynomolgus monkey (Macaca fascicularis) is now commonly used for experimentation due to its convenient size, rather omnivorous natural diet, and ability to stay healthy in captivity. It is the animal of choice in toxicological studies on drugs or chemicals (as second, nonrodent species), as well as in AIDS research and studies on vaccine development and safety. Also, the common marmoset (Callithrix jacchus) is currently increasingly selected as laboratory primate in many fields of biomedical research, including toxicology. Whenever only small amounts of a drug are available to run a preclinical toxicological study, required by regulatory authorities before the marketing of a new drug, the marmoset may be the appropriate species due to its small size. In contrast, rhesus monkeys (Macaca mulatta) that were formerly more frequently used in toxicological testing now only rank third in use behind the two other species. Other primate species, e.g., African green monkeys (Chlorocebus aethiops) or pigtailed macaques (Macaca nemestrina) may be used for specific scientific questions. This chapter will primarily focus on the three types of primates most widely used in toxicology.