Consideration of the Development of the Gastrointestinal Tract in the Choice of Species for Regulatory Juvenile Studies.

ABSTRACT

Although the rat is close to being the automatic choice for regulatory juvenile toxicity studies, there are several shortcomings in this model. Choosing a species should take into serious consideration the importance of gastrointestinal tract development in the period before weaning as this may have a major effect on exposure. A comparison of the anatomical changes in the stomach and small intestine of mini-pig and rat show that the mini-pig is a far closer model for man than is the rat, although there are a few unusual aspects of small intestinal development in the mini-pig. Considerations of the development of the gastrointestinal tract and choice of species have the potential to affect safety assessment and should be a prime consideration when planning an investigation. Birth Defects Research 11056-62, 2018. © 2017 Wiley Periodicals, Inc.