Enzymatic response of Callinectes sapidus and Geukensia demissa as biomarkers for pesticide exposure

UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
Heather R. Caveny (Creator)
The University of North Carolina Wilmington (UNCW )
Web Site: http://library.uncw.edu/

Abstract: The widespread commercial and private use of organophosphate (OP) and carbamate pesticides, and their subsequent presence in aquatic ecosystems, is cause for concern in terms of both environmental and human health. Disruption of acetylcholinesterase (AChE) activity is a primary mode of acute toxicity of OP pesticides to non-target organisms, and this inhibition has been used in limited settings as a biomarker of OP/carbamate exposure. A second hydrolyzing enzyme, carboxylesterase (CBE), is also inhibited upon exposure to these compounds; used in conjunction with AChE activity, it may provide a more inclusive biomarker than AChE activity alone. In this study, two aquatic invertebrates were studied as potential indicator species of pesticide pollution. Enzymes were characterized for Michaelis-Menten kinetics, and in vitro and in vivo tests were conducted to assess the impact of OP and carbamate compounds on each enzyme, in both hemolymph and tissue in both species. In general, the blue crab, Callinectes sapidus, showed higher mortality at lower concentrations than did the ribbed mussel, Geukensia demissa. However, G. demissa showed more significant enzyme inhibition at sub-lethal concentrations, making it a more effective indicator of a potential threat. Although enzyme inhibition rarely occurred at environmentally relevant concentrations of a single contaminant, the more probable presence of multiple or chronic stressors could effect a measurable response in situ.

Additional Information

A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment Of the Requirements for the Degree of Master of Science
Language: English
Date: 2009
Blue crab--Effect of pollution on, Callinectes--Effect of pollution on, Environmental toxicology, Mussels--Effect of pollution on, Pesticides--Toxicology
Mussels -- Effect of pollution on
Blue crab -- Effect of pollution on
Pesticides -- Toxicology
Environmental toxicology
Callinectes -- Effect of pollution on

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