Micromass Culture of Midbrain Cells and its Relevance to in Vitro Mechanistic Studies*

Abstract

The relationship between ethylenethiourea (ETU)-induced malformations of cultured rat whole embryos and the alterations of midbrain (MB) cells was investigated and species-specific ETU-induced alterations between rat and mouse MB cells were determined.Herefore, we developed new methods for monitoring teratogenic activities in serum fluids without heat treatment. The serum samples were prepared from rats and mice given ETU, and ETU-teratogenicity was evaluated in both species. We determined that the different sensitivity of the midbrain of the rat and mouse may be the main reason that ETU was teratogenic in rats but not in mice.Next, we showed that MB-cultures are unsuitable for estimating the teratogenic potential of arotinoids. MB differentiation was adversely affected only at concentrations which caused cell death. Finally, we demonstrated that the embryolethal action of new herbicides is not detectable in the micromass teratogenic test. However, the V79 colony assay may be useful for preliminary screening of embryolethal effects of herbicides.OX-#, ~~~~t~ TI13 %g$g?LZE/%%l 5-45 t 158 %%% k H %El ffl R 1-18-1

Neural differentiation of midbrain cells on various protein‐immobilized polyethylene films

“…There were many kinds of cells in this MB cell culture system, because primary cells collected from mouse embryos have been suggested to differentiate nerve cells on the layer of other cells, such as mesenchymal cells, in this system. 2 It is possible that growth of mesenchymal cells was improved by the surface modification with the cell-adhesive RGDS peptide, resulting in improved differentiation of the nerve cells. This suggests that interaction between mesenchymal cells normally grown on a substrate, and nerve cells on the layer of the mesenchymal cells, is one of the important factors in the differentiation of MB cells.…”

“…The MB micromass culture system is a convenient in vitro assay originally developed for in vitro teratogenicity tests. 2 In addition, it has already been suggested that the differentiation level of the MB cells might be related to GJIC inhibitory activity of the biomaterial. 3 In this study, we examined the effect of surfaces modified with various kinds of proteins on cell differentiation under in vitro experimental conditions to clarify suitable surface characteristics for producing excellent biomaterials.…”

3‐Chloro‐4‐(dichloromethyl)‐5‐hydroxy‐2(5H)‐furanone (MX) as a Direct‐Acting Teratogen in Micromass in vitro Tests

“…The micromass in vitro test with rat embryo midbrain (CNS) and limb bud cells has been shown to have a high predictability for teratogens (Flint and Orton, 1984) and to be useful for mechanistic studies (Tsuchiya et al, 1992). We found in a previous study (Teramoto et al, 1998) that MX had a strong inhibitory effect on cell differentiation in the micromass in vitro test.…”