Metabolic activation capacity by primary hepatocytes expands the applicability of the embryonic stem cell test as alternative to experimental animal testing.
The murine embryonic stem cell test (EST) represents a validated alternative method for in vivo embryotoxicity testing. In the present study, primary hepatocytes were combined with the EST by a preincubation approach to improve its predictivity on bioactivation caused teratogenicity. As substances the well-known proteratogens cyclophosphamide (CPA) and valpromide (VPD) were used. The embryotoxic potential of CPA was detected by a strong decrease of the resulting ID(50)-concentration (50% inhibition of ES cell differentiation) after incubation with murine hepatocytes. Interspecies variation in metabolism was detected by testing VPD. After incubation of VPD with murine hepatocytes no inhibition of ES cell differentiation was observed, since hardly any teratogenic VPD metabolites were formed. In contrast, with human hepatocytes a significant conversion of VPD into the teratogen valproic acid (VPA) was observed. In summary we developed a co-culture approach for embryotoxicity testing, whereby the test compounds were incubated with hepatocytes and the supernatant was added to the ES cell culture to obtain a dose dependency of the preincubated test substances.
Hettwer
Michael
M
Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Hannover, Germany. michael.thomas.hettwer@tiho-hannover.de
Reis-Fernandes
Marcos A
MA
Iken
Marcus
M
Ott
Michael
M
Steinberg
Pablo
P
Nau
Heinz
H
D000826:Animal Testing Alternatives; D000818:Animals; D041702:BALB 3T3 Cells; D002454:Cell Differentiation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D018920:Coculture Techniques; D004305:Dose-Response Relationship, Drug; D053595:Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D022781:Hepatocytes / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects; D015203:Reproducibility of Results; D013723:Teratogens / Q000633:toxicity*; D018675:Toxicity Tests / Q000379:methods* / Q000592:standards
D013723:Teratogens