Related Experiment Video
Updated: Aug 15, 2026
Isolation of Primary Mouse Hepatocytes for Nascent Protein Synthesis Analysis by Non-radioactive L-azidohomoalanine Labeling Method
Published on: October 23, 2018
Interspecies variability of TNP-470 metabolism, using primary monkey, rat, and dog cultured hepatocytes
L Placidi1, E C Scott, G de Sousa
1Department of Pharmacology and Toxicology, University of Alabama at Birmingham 35294-0019, USA.
Abstract:
The biotransformation of TNP-470 [O-(chloroacetylcarbamoyl)fumagillol; AGM 1470], a potent in vitro inhibitor of angiogenesis, was investigated in primary cultured hepatocytes isolated from different species, including monkey, dog, and rat, as well as in microsomal fractions of various monkey tissues. Previous metabolic studies by our group using human hepatocytes in primary culture demonstrated that TNP-470 was primarily metabolized to M-IV through an ester cleavage, with subsequent conversion of M-IV to M-II by microsomal epoxide hydrolase. Additional studies using monkey liver microsomes demonstrated that M-II was then glucuronidated by uridine-5'-diphosphoglucuronyl transferase, leading to the formation of M-III. Three other, as yet unidentified, metabolites, labeled M-I, M-V, and M-VI, were also detected. Similarly to findings in human hepatocytes, the predominant extracellular metabolite was M-II in all species studied. Minor interspecies variability was observed in the total amount of drug biotransformed by hepatocytes, but some variability was detected in the metabolic pattern of TNP-470 in monkey hepatocytes, compared with rat or dog hepatocytes. In monkey hepatocytes, as previously observed in human cells, TNP-470 was metabolized to six derivatives, labeled M-I, M-II, M-III, M-IV, M-V, and M-VI, whereas the latter metabolite was not observed in dog or rat extracellular medium. Extrahepatic metabolism of TNP-470 was also studied using monkey intestine, kidney, and lung microsomes, which demonstrated that, under these experimental conditions, TNP-470 was extensively metabolized to four derivatives, i.e. M-I, M-II, M-III, and M-IV, with M-III being detected only in liver samples. These studies suggest that the metabolism of TNP-470 in monkeys appears to be most closely related to that observed in humans. Although the individual quantitative metabolic profiles were quite different in various animal species, only one metabolite, namely M-VI, was not detected in either dog or rat hepatocytes in vitro.
Insights
The metabolism of TNP-470, an angiogenesis inhibitor, was studied in various animal species. Monkey metabolism closely resembles human biotransformation, with M-II as the predominant metabolite across species.
Area of Science:
- Pharmacology
- Drug Metabolism
- Biochemistry
Background:
- TNP-470 (O-(chloroacetylcarbamoyl)fumagillol; AGM 1470) is a potent in vitro inhibitor of angiogenesis.
- Previous studies in human hepatocytes identified key metabolic pathways for TNP-470.
Purpose of the Study:
- To investigate the biotransformation of TNP-470 in primary cultured hepatocytes and microsomal fractions from different species (monkey, dog, rat).
- To compare the metabolic profiles of TNP-470 across species and with human metabolism.
Main Methods:
- Primary cultured hepatocytes from monkey, dog, and rat were used.
- Microsomal fractions from various monkey tissues (liver, intestine, kidney, lung) were analyzed.
- Metabolites were identified and quantified, including M-I through M-VI.
Main Results:
- The predominant extracellular metabolite in all species studied was M-II.
- Monkey TNP-470 metabolism showed similarities to human metabolism, producing six derivatives (M-I to M-VI).
- Metabolite M-VI was not detected in dog or rat hepatocytes; M-III was only found in liver samples.
Conclusions:
- The metabolism of TNP-470 in monkeys is most closely related to that observed in humans.
- While quantitative metabolic profiles varied between species, M-II is a consistent major metabolite.
- Understanding interspecies metabolic differences is crucial for preclinical drug development.
