The effect of thermal acclimation on the activity of arylhydrocarbon hydroxylase in rainbow trout (Oncorhynchus mykiss).
1. The possibility that temperature acclimation (to 10 or 18 degrees C for 28 days) would alter the cytochromes P-450 of rainbow trout was addressed. 2. The specific content of LM4b (P-450 IA1), the trout isozyme responsible for activation of polynuclear aromatic hydrocarbons, was lower in 18 degrees C fish than it was in 10 degrees C fish. 3. Kinetic analysis of aryl hydrocarbon hydroxylase indicated that, while thermal acclimation caused no change in Vmax, it lowered the apparent Km of this enzyme for benzo[a]pyrene when assayed at acutely shifted temperatures. 4. Thermal acclimation of fish may have significance when feral populations are subjected to acute temperature shifts.
Carpenter
H M
HM
Oak Creek Laboratory of Biology, Department of Fisheries and Wildlife, Oregon State University, Corvallis 97331.
Fredrickson
L S
LS
Williams
D E
DE
Buhler
D R
DR
Curtis
L R
LR
D000064:Acclimatization; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000302:isolation & purification / Q000378:metabolism*; D015153:Blotting, Western; D003577:Cytochrome P-450 Enzyme System / Q000302:isolation & purification / Q000378:metabolism*; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008862:Microsomes, Liver / Q000201:enzymology*; D013696:Temperature; D014337:Trout / Q000502:physiology*
D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System; D001189:Aryl Hydrocarbon Hydroxylases