Ultrastructural modifications in cultured fetal quail hepatocytes exposed to pesticides and PCBs.

There is increasing interest in cultured hepatocytes as a tool for solving toxicological and pharmacological problems while reducing laboratory animal experimentation. In the present study, fetal hepatocytes from the Japanese quail (Coturnix coturnix japonica) were used as an in vitro alternative model for evaluating the effects of PCBs and various pesticide-type chemicals on cell ultrastructure. Major alterations were demonstrated. The most striking effects of toxicants were an increase in the number of cisternae of the rough endoplasmic reticulum (RER), various alterations of mitochondrial morphology, a decreased glycogen content, vacuolization of the cytoplasm, and the appearance of concentric membrane arrays (CMA's), also called myelin-like figures. Other changes were sometimes observed, such as altered cell junctions, an increased lipid content, deformations of the nuclei, or the appearance of crystalline structures. These ultrastructural modifications seem to be dose-dependent. The present in vitro findings are validated by similar observations previously made in vivo on Japanese quail. They confirm the effectiveness of this technique as a biomonitoring tool for the evaluation of environmental quality. Yet the multiplicity of possible toxic effects, even for xenobiotics of a same category, makes it necessary to screen additional indicators of toxicity, such as the detoxifying activity of monooxygenases.