Regional distribution of microsomal xenobiotic and steroid metabolism in kidney microsomes from rainbow trout.
The regional distribution of microsomal cytochrome P-450-mediated reactions with exogenous and endogenous substrates in the kidney of rainbow trout was studied. The cytochrome P-450-dependent 7-ethoxyresorufin- and 7-ethoxycoumarin-0-deethylase activities were significantly higher (3-4 and 10-14 fold, respectively) in the trunk kidney than in the head kidney, whereas ethylmorphine-N-demethylase activity was evenly distributed along the kidney. The microsomal cytochrome P-450-dependent steroid hydroxylases and steroid reducing enzymes when using androstenedione as substrate also exhibited a regional distribution in trout kidney. The 6β- and 16-hydroxylase activities as well as the 5α-reductase and 17 hydroxysteroid oxidoreductase activities were higher in the anterior part of the trunk kidney than in the head kidney and posterior trunk kidney.
Department of Zoophysiology, University of Göteborg, Box 25059, S 400 31, Göteborg, Sweden.
M
M
Pesonen
T
T
Hansson
L
L
Förlin
T
T
Andersson