Health & Environmental Research Online (HERO)


Print Feedback Export to File
8435009 
Journal Article 
Differential distribution of the mixed-function oxidase activities in rabbit kidney 
Zenser, TV; Mattammal, MB; Davis, BB 
1978 
Yes 
Journal of Pharmacology and Experimental Therapeutics
ISSN: 0022-3565
EISSN: 1521-0103 
AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS 
BETHESDA 
207 
3 
719-725 
English 
731427 
WOS:A1978GF98100006 
Microsomal mixed-function oxidase activities in renal cortex, outer medulla and inner medulla were characterized and compared to liver in control and 3-methylcholanthrene-treated adult rabbits. Renal cytochrome P-450 was more sensitive to induction by 3-methylcholanthrene than liver with a 5-fold increase in cortical content observed. Outer medullary cytochrome P-450 content was only demonstrated after 3-methylcholanthrene treatment, but inner medullary cytochrome P-450 content was not observed by spectral analysis. In control rabbits, renal aryl hydrocarbon activities were not measurable. Treatment with 3-methylcholanthrene resulted in the appearance of cortical and outer medullary aryl hydrocarbon hydroxylase but not of dimethylaniline demethylase activities. Aminopyrine demethylase activity was increased by 3-methylcholanthrene in renal cortex and outer medulla but not in liver. Lauric acid hydroxylase was the only specific mixed-function oxidase activity observed in the inner medulla. The renal cortex contained the highest lauric acid hydroxylase activity with liver and inner medulla exhibiting the least activity. Lauric acid hydroxylase activity was inhibited by carbon monoxide and metyrapone in each area of the kidney. By contrast, α-naphthoflavone inhibited cortical and outer medullary but not inner medullary lauric acid hydroxylase activity in 3-methylcholanthrene-treated rabbits. These results demonstrate the presence of specific mixed-function oxidases in each area of the kidney. The different sensitivity of renal and hepatic oxidases to 3-methylcholanthrene induction suggests that the genetic expression of these enzymes in kidney and liver may be different.