Use of rainbow trout primary epidermal cell cultures as an alternative to immortalized cell lines in toxicity assessment: A study with nonoxynol

Increased concern has centered around environmental contaminants that exert estrogenic effects. A class of nonionic surfactants, the nonylphenol ethoxylates (such as the compound nonoxynol), are an example of one such group of contaminants. We studied the effects of nonoxynol (alpha-(4-nonylphenyl)-omega-hydroxypoly-(oxy-1-ethanediyl)) on an epithelial primary culture. The culture system that was employed is a development of an in vitro technique for the culture of rainbow trout (Onchorynchus mykiss) epithelium, one that allows for the culture of both epithelial cells and goblet cells. The LC50 after 24 h was found to be 16.6 mu mol/L. The LC50 after 48 h was 12.9 mu mol/L. Nonoxynol was found to exhibit an acute lethal dose of 75 mu mol/L. A decrease in the number of goblet cells present in the system was observed as exposure to nonoxynol increased. Nonoxynol was found to kill epithelial cells mainly by necrosis. A comparative study of the effects of nonoxynol on the epithelium papulosum cyprini cell line was also carried out. The LC50 of nonoxynol on this cell type was 41 mu mol/L, with an acute lethal dose of 10 mu mol/L.