The effect of pH changes of water on the hepatic metabolism of xenobiotics in fish.
In order to determine the effect of pH changes of water on the metabolism of xenobiotics, fish were exposed for 8 hours to the acidic water (pH3). Two fish species were used, lavaret, (Coregonus lavaretus), and splake (Salvelinus fontinalis X Salvelinus namaycush). The metabolism of xenobiotics was monitored by analyzing aryl hydrocarbon hydroxylase, epoxide hydrase and ethoxycoumarin O-deethylase activities as well as the activity of UDPglucuronosyltransferase using both p-nitrophenol and 4-methylumbelliferone as aglycones. A difference was found between species in measured basal activities. The aryl hydrocarbon hydroxylase activity, epoxide hydrase activity and ethoxycoumarin O-deethylase activity were higher in the splake than in the lavaret. No clearcut differences were detected in UDPglucuronosyltransferase activities. When fish were exposed to water at pH 3, the aryl hydrocarbon hydroxylase activity and epoxide hydrase activity in the splake were lower than in the control fish. The ethoxycoumarin O-deethylase activity was higher in the lavarets at pH 3 than in the controls. The UDPglucuronosyltransferase activity was higher in both splakes and lavarets exposed to pH 3 when analyzed after trypsin digestion of microsomes and with 4-methylumbelliferone as an aglycone.
D000818:Animals; D005399:Fishes / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism*; D013045:Species Specificity; D014867:Water
D014867:Water