CATALYTIC ACTIVITY AND IMMUNOHISTOCHEMICAL LOCALIZATION OF FLAVIN-CONTAINING MONOOXYGENASE IN RAT-KIDNEY

The presence of flavin-containing monooxygenase activity was examined in rat kidney microsomes using N,N-dimethylaniline and methimazole as substrates. Western immunoblot analysis using antisera to porcine live r and rabbit lung flavin-containing monooxygenase indicated immunologi cal cross-reactivity between rat kidney, porcine liver and rabbit lung flavin-containing monooxygenase. Immunohistochemical studies using an tisera to rabbit lung flavin-containing monooxygenase demonstrated loc alization of this enzyme in the proximal and distal convoluted tubules of the renal cortex, the collecting ducts in the renal medulla, but n ot the glomeruli. This observation indicates the co-localization of fl avin-containing monooxygenase and cytochrome P-450 in the metabolicall y active and absorptive compartment of the renal parenchyma.