Species Comparison

Results

Cytochrome P450 metabolism can vary widely from one species to another, so determining the best animal model is important for pharmacokinetic and toxicity studies.

Coumarin Example

For example, coumarin is biotransformed in the human to 7-hydroxycoumarin, which is then conjugated for excretion without any toxicity.  When given to rats, however, coumarin biotransforms into an epoxide, leading to a reactive aldehyde with hepatotoxic effects.  In this example, rats would make a poor model to predict the result of human biotransformation.

Species differences in drug metabolism can be assessed by studying the in vitro metabolism of a drug by hepatocytes from a variety of species of laboratory animals (e.g., monkey, dog, rabbit and rat). This analysis compares metabolic profiles from humans and animal species in order to identify the most relevant animal model for pharmacokinetic and toxicity studies.

We offer species comparison as a contract service, and we offer product kits for customers who perform their own in-house comparisons.

XenoTech's species comparison kits are offered in two formats:

• Microsomes
• Cryopreserved hepatocytes

Results

The charts below show a comparison of alfentanil N-dealkylation and testosterone 6β-hydroxylation activities in liver microsomes from various species.