In vitro studies of acute toxicity mechanisms and structure-activity relationships of nonionic surfactants in fish

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:40022

Bodishbauah, D F ^[1]

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1. Duke Univ. Marine Lab., Beaufort, NC (United States)

In fish, gills are believed to be a primary target for a number of toxicants. Gills perform the essential systemic functions of gas exchange, waste elimination, and ion/pH balance, and are exposed to ambient environmental toxicant levels. Qualitative gill morphology changes are easily observed, but quantitative measures of impaired function are difficult. This in vitro technique utilizes the opercular epithelium of the mummichog, Fundulus heteroclitus, as a surrogate for gill epithelium in mechanistic toxicity and structure-activity studies. This model has long been used by electrophysiologists studying osmoregulation in marine fish. Effects on trans-epithelial potential (TEP) and/or short-circuit current (I{sub sc}) across the opercular epithelium can be made for any pollutant of interest, using an epithelial voltage clamp and Ussing chamber. The nonionic synthetic surfactant class, alkylphenol ethoxylates, were chosen as a model toxicant class to test this experimental model. Synthetic surfactants are ubiquitous waterborne pollutants, with annual North American usage approaching eight billion pounds. Surfactants are recognized as potent, acute gill toxicants in fish. The exact mechanism of toxicity has yet to be elucidated. These compounds proved to be potent inhibitors of both TEP and I{sub sc} in vitro, at dose levels comparable to those causing lethality, suggesting that impaired osmoregulation plays a role in their acute toxicity. Similar structure-activity relationships were found for the endpoints of acute lethality to F. heteroclitus and impaired in vitro epithelial transport.

• OSTI ID: 40022
• Report Number(s): CONF-9410273--
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
FISHES
GILLS
MEMBRANE TRANSPORT
MORPHOLOGICAL CHANGES
SENSITIVITY
STRUCTURE-ACTIVITY RELATIONSHIPS
SURFACTANTS
TOXICITY
WATER POLLUTION