Responding to the demand of animal testing reduction and effective risk assessment of chemical substances,
in vitro testing methods using hepatocytes or liver S9 fractions from rainbow trout have been established recently (OECD TG319A&B).
In this test, in vitro metabolism rates of chemical substances are determined
and the measured rates can be extrapolated to in vivo metabolism rates in fish with PBTK models.
Therefore, using in vivo metabolism rates and prediction models,
we can evaluate the bioaccumulation potential of chemical substances faster and easier,
compared with in vivo tests such as OECD TG305 or regulation tests.
However, the application of this method was actually limited to rainbow trout and there is not sufficient data regarding in vitro test.
Then, it is needed to compile in vitro test data of fish species other than rainbow trout
and the application examples for bioaccumulation assessment of chemical substances to be used in regulation.
For these issues, we have addressed to prepare Carp S9 fractions and enzyme activity measurement methods
and to measure in vitro metabolism rates of chemical substances with prepared S9 fractions of Carp or purchased S9 fractions of Carp and Rainbow trout.
In this presentation, we will mainly introduce our efforts on this in vitro testing.