Localization of cytochrome P-450 in the colonic mucosa of 3-methylcholanthrene-pretreated and untreated rats. An immunohistochemical study.
Immunohistochemical localization of cytochrome P-450 in the colonic mucosa of 3-methylcholanthrene-pretreated and untreated rats was studied by indirect fluorescent antibody staining technique. A polyclonal antibody for cytochrome P-450MC purified from hepatic microsomes of 3-methylcholanthrene-pretreated rats was used for this experiment. A strong immunofluorescence was found to be localized in the cytoplasm of the surface epithelium of the mucosa in the colon of 3-methylcholanthrene-pretreated rats. A faint immunofluorescence was also observed in the epithelium of untreated rats. 7-Ethoxycoumarin O-deethylase activity of colonic microsomes was significantly enhanced by 3-methylcholanthrene-pretreatment in parallel with an increase in the intensity of immunostaining for cytochrome P-450MC in Western blotting analysis. This is the first report on the localization of cytochrome P-450 in the colonic mucosa.
Tamura
S
S
Second Department of Internal Medicine, Osaka University Medical School, Japan.
Kawata
S
S
Okamoto
M
M
Tarui
S
S
D015660:7-Alkoxycoumarin O-Dealkylase; D000818:Animals; D003106:Colon / Q000032:analysis* / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis*; D007150:Immunohistochemistry; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology*; D008861:Microsomes / Q000201:enzymology; D010105:Oxygenases / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains
D008748:Methylcholanthrene; D003577:Cytochrome P-450 Enzyme System; D010105:Oxygenases; D015660:7-Alkoxycoumarin O-Dealkylase