The evaluation of developmental toxicity of chemicals exposed occupationally using whole embryo culture

Abstract

The purpose of this study was to employ the whole embryo culture (WEC) system to evaluate the developmental toxicity of industrial chemicals. Five chemicals including lead, cadmium, vinyl chloride, 1,2-dichloroethan, and carbon disulphide were tested in our laboratory both in vitro and in vivo (except lead). In vitro studies showed that cadmium and lead were teratogenic in the rat; whilst carbon disulphide, 1,2-dichloroethan and vinyl chloride mainly induced embryo growth retardation. The in vitro effects on development of the five industrial chemicals were similar to the effects in vivo. The in vitro effects were studied by three different exposure routes, direct exposure - chemicals added to the culture medium; indirect exposure - serum prepared from treated rats then used as culture medium, and pre-exposure embryos treated maternally then explanted into control (untreated) culture medium. Comparing these three different exposure routes suggests that the last exposure route is the most effective when using WEC to evaluate developmental toxicity of industrial chemicals. The effects on embryo development of culturing in sera prepared from subjects occupationally exposed to antineoplastic drugs (ADs) was also tested by the WEC system. Embryos were cultured with human serum that was thought to contain ADs or ADs' metabolic materials (serum taken from nurses routinely handling ADs), to evaluate the effects of ADs on embryo development. Embryos (9.5-day) cultured with serum from 11 female nurses who had been handling ADs for 2-17 years in the oncology department all survived, but showed slight growth retardation. Embryos cultured with serum from 30 healthy and unexposed people served as controls and embryo development in their serum was normal.