Juvenile toxicity testing

Published on May 30, 2021   48 min

Other Talks in the Category: Methods

Welcome to the module on juvenile toxicity testing prepared by myself, Alan Hoberman and Elise Lewis both worked for Charles River Laboratories. I am the Global Director for juvenile toxicology. I conducted actually one of the first juvenile toxicity tests in rodents back in the late '70s.
But it really wasn't until the 2000s that guidance documents from first the USFDA in 2006 and then Europe in 2008, in Japan in 2012, were issued to really look at juvenile toxicology testing. The regulatory status today involves a harmonized guideline, the ICHS 11 guideline, which I have listed here is in progress, but actually, step four of the progress was issued in April of 2020 and will become law in various parts of the world over the next year or so.
First we're going to talk about species selection, one of the important parts of doing a juvenile toxicology study, and we use rodents and non-rodents.
For juvenile toxicology, there are number of species that can be used and we're going to talk a lot about why we use one species over another species when one is appropriate and the other one is not appropriate. But you can see we use everything from rats, mice, hamsters, guinea pigs, dogs, rabbits, non-human primates, and mini-pigs nowadays. Many times what we're going to select as a species will be what we use in the general toxicology work with some limitations that we're going to talk about.
First, let's look at some of the desirable characteristics of rodents and non rodents. Well, we know the most about rodents. We use rats most often in our testing. We know, we understand when estrous cycle good reproductive capacity, litters gives us large amount of animals to work with. They grow very quickly. We can look at the skeletal growth. We understand a lot about their immune systems and neuro-behavioral assessments are possible. Similar things can be done with mice. Non rodents. We think of the non-human primate, but we try to avoid using that as much as we can. Although many of the characteristics are similar to humans, it's hard to do neuro behavioral screening with them. Although there's something similar to humans, many pigs are becoming more and more popular nowadays. There are several anatomical maturation characteristics are similar to humans and some things that are different. Rabbits at times can be appropriate, dogs can be appropriate at times. We're going to talk about a lot of that as we go through this module.