title: Acute and chronic ethanol exposure differentially alters alcohol dehydrogenase and aldehyde dehydrogenase activity in the zebrafish liver.
abstract: Chronic ethanol exposure paradigms have been successfully used in the past to induce behavioral and central nervous system related changes in zebrafish. However, it is currently unknown whether chronic ethanol exposure alters ethanol metabolism in adult zebrafish. In the current study we examine the effect of acute ethanol exposure on adult zebrafish behavioral responses, as well as alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity in the liver. We then examine how two different chronic ethanol exposure paradigms (continuous and repeated ethanol exposure) alter behavioral responses and liver enzyme activity during a subsequent acute ethanol challenge. Acute ethanol exposure increased locomotor activity in a dose-dependent manner. ADH activity was shown to exhibit an inverted U-shaped curve and ALDH activity was decreased by ethanol exposure at all doses. During the acute ethanol challenge, animals that were continuously housed in ethanol exhibited a significantly reduced locomotor response and increased ADH activity, however, ALDH activity did not change. Zebrafish that were repeatedly exposed to ethanol demonstrated a small but significant attenuation of the locomotor response during the acute ethanol challenge but ADH and ALDH activity was similar to controls. Overall, we identified two different chronic ethanol exposure paradigms that differentially alter behavioral and physiological responses in zebrafish. We speculate that these two paradigms may allow dissociation of central nervous system-related and liver enzyme-dependent ethanol induced changes in zebrafish.
authors.affiliation: Department of Cell and Systems Biology, University of Toronto Mississauga, Canada. Electronic address: stevenhuy.tran@mail.utoronto.ca.
authors.forename: Steven
authors.initials: S
authors.lastname: Tran
authors.affiliation: Department of Psychology, University of Toronto Mississauga, Canada.
authors.forename: Magda
authors.initials: M
authors.lastname: Nowicki
authors.affiliation: Department of Psychology, University of Toronto Mississauga, Canada.
authors.forename: Diptendu
authors.initials: D
authors.lastname: Chatterjee
authors.affiliation: Department of Cell and Systems Biology, University of Toronto Mississauga, Canada; Department of Psychology, University of Toronto Mississauga, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Gerlai
mesh_terms: D000367:Age Factors; D000426:Alcohol Dehydrogenase / Q000378:metabolism*; D000444:Aldehyde Dehydrogenase / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008124:Locomotion / Q000187:drug effects; D008297:Male; D013997:Time Factors; D015027:Zebrafish
chemical_list: D002492:Central Nervous System Depressants; D000431:Ethanol; D000426:Alcohol Dehydrogenase; D000444:Aldehyde Dehydrogenase
keywords: Alcohol dehydrogenase; Aldehyde dehydrogenase; Chronic ethanol; Tolerance; Zebrafish