Related Experiment Video
Updated: Aug 7, 2026

Quantification of the Immunosuppressant Tacrolimus on Dried Blood Spots Using LC-MS/MS
Published on: November 8, 2015
Species differences in the hepatic and intestinal metabolism of cyclosporine
R D Whalen1, P N Tata, G J Burckart
1Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, PA 15261, USA.
Abstract:
1. Cyclosporin A (cyclosporine, CSA) is an immunosuppressive drug with a narrow therapeutic index. In the present study the metabolism of CSA was investigated in the liver and small intestinal microsomes obtained from rat, hamster, rabbit, dog, baboon and man by measuring the disappearance of CSA and the formation of the principal metabolites of CSA, namely hydroxylated and N-demethylated CSA. 2. CSA was metabolized at a very slow rate (2-8% metabolism in 30 min) in rat liver microsomes whereas microsomes from dog livers were very efficient (70-100% metabolism in 30 min) in metabolizing CSA. Hydroxylation and N-demethylation accounted for most of the CSA metabolized in all the species tested. 3. Microsomes from the small intestine produced qualitatively a similar metabolic profile as compared with the microsomes from the liver, but at a slower rate in all the species tested. The relative importance of the different metabolic pathways, however, differed between species. 4. This study points to the importance of recognizing the similarities and the differences in the metabolism of CSA in different species when data from animal studies are extrapolated to man.
More Related Videos
10:44Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures
Published on: March 28, 2017
10:01Structure-Guided Design and Development of Novel Cyclophilin A Inhibitors and Ganoderiol-F Derivatives: An In-Silico Approach
Published on: June 23, 2026
Related Concept Videos
Factors Affecting Drug Biotransformation: Biological
Species differences: Variations in enzyme systems across species can cause disparities in drug metabolism. For instance, humans may metabolize certain drugs faster than rodents, altering therapeutic effects.
Strain differences: Genetic variations within a species can result in differing enzyme activity, impacting drug response and toxicity. For example, some mouse strains may...
Hepatic Drug Excretion: Enterohepatic Cycling
Post-release drugs and metabolites can be reabsorbed into the body from the intestine. For conjugated metabolites like glucuronides, reabsorption requires enzymatic hydrolysis by intestinal microflora. This...
Pharmacokinetics in Pediatric Patients: Drug Metabolism
Effect of Hepatic Disease on Pharmacokinetics: Drug Dosing and Hepatic Blood Flow
Effect of Hepatic Disease on Pharmacokinetics: Active Drug, Metabolite and Fraction of Metabolized Drug
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes