Pentachlorophenol disrupts steroid hormone metabolism at concentrations that reduce survival and fecundity of Daphnia magna
- North Carolina State Univ., Raleigh, NC (United States). Dept. of Toxicology
Alterations in steroid metabolism by environmental endocrine disrupters can significantly affect steroid hormone-dependent processes such as growth and reproduction. Exposure to pentachlorophenol (PCP) has been shown to elicit a variety of endocrine-related adverse effects. The present study was undertaken to establish whether concentrations of PCP that adversely affect survival, growth, or reproduction of Daphnia magna during chronic exposure also elicit changes in steroid hormone metabolism. Survival and/or reproduction of daphnids was significantly reduced from exposure to 1.0, 0.50 and 0.25 mg/L PCP. Following chronic exposure to PCP, daphnids were incubated with [{sup 14}C]testosterone and the testosterone metabolites eliminated were identified and quantified. The rate of testosterone hydroxyl-metabolite elimination was not significantly different from controls. However, elimination of two of the glucose-conjugated metabolites of testosterone decreased in a PCP concentration-dependent manner. Adult daphnids were next exposed to these concentrations of PCP for only 48 hours and effects on steroid metabolism assessed. As observed following chronic exposure, PCP had no effect on the elimination of hydroxyl-metabolites. However, elimination of glucose and sulfate conjugates of testosterone were inhibited in a concentration-dependent manner. These results demonstrate that, (1) PCP alters steroid biotransformation activities at concentrations that affect survival and reproduction, and (2) effects on steroid metabolism can be detected following short-term exposure to PCP. Thus, this biochemical parameter may serve as a biomarker of chronic toxicity associated with PCP.
- OSTI ID:
- 398178
- Report Number(s):
- CONF-9511137--; ISBN 1-880611-03-1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Identification of multiple steroid hydroxylases in Daphnia magna and their modulation by xenobiotics
Progressive effects of silver nanoparticles on hormonal regulation of reproduction in male rats