Assessment of embryotoxic potential of mixtures of environmental chemicals using rat embryo limb bud cell cultures

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 06670394
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Hygiene
• Research Institution: National Institute for Environmental Studies
• Principal Investigator: YONEMOTO Junzo National Institute for Environmental Studies, Regional Environment Senior Division Researcher, 地域環境研究グループ, 主任研究員 (30072664)
• Project Period (FY): 1994 – 1995
• Keywords: Limb bud cell cultures / Environmental chemicals / Embryotoxicity / Toxicity assessment of mixtures / Organochlorine compounds / Isobole diagram

Research Abstract

The objective of this study was to evaluate the usefulness of rat embryo limb bud cell cultures (LBC) for analyzing joint embryotoxic action of chemical contaminants in the environment. The mode of joint action of chemicals in LBC can be visualized using the toxic unit model and an isobole diagram.
The embryotoxicity of nine organochlorine compounds commonly detected in the environment were screened using LBC.These chemicals were p-dichlorobenzene (pDCB), o-dichlorobenzene (o-DCB), p-chloroaniline(pCA), 3,4-dichloroaniline (DCA), tris(2-chloroethyl) phosphate, 2,5-dichlorophenol (DP), 2,5-dichloroanisole (DA), Triclosan (IR) and Triclocarban (TC). The embryotoxicity of binary mixtures of these chemicals were also screened and analyzed using LBC and isobole diagram. Mixture of IR-TC showed additive joint action. Mixtures of pDCB-TCEP and pDCB-pCA showed less than additive joint action for cell proliferation while mixture of pDCB-DP showed less than additive joint action for cell differentiation.
As LBC can assess the joint action for cell proliferation, for cell differentiation and for their ratio of the former to the latter (P/D ratio), LBC is useful for evaluating embryotoxic potential of chemical mixtures.