title: Differences between small and large intestine and liver in the inducibility of microsomal enzymes in response to stimulation by phenobarbitone and betanaphthoflavone in the diet.
abstract: Rats were fed either sodium phenobarbitone (PB) or betanaphthoflavone (BNF) for seven days. Deethylation of 7-ethoxyresorufin ( 7ERR ) and 7-ethoxycoumarin ( 7EC ) was measured in small and large intestine and liver, and cytochrome P-450 in liver. Our semi-purified diet was shown to produce minimal levels of intestinal deethylation activity. BNF was added to the semi purified diet and fed at levels from 0.1 to 100 mg BNF/kg of diet. Significant (P less than 0.05) induction of deethylation in small intestine was seen at all dose levels, ranging from 2-fold at 0.1 mg/kg diet to greater than 100-fold at 100 mg/kg diet. A 3-fold increase was also seen in the large intestine at 50 mg/kg. A significant increase in hepatic deethylation was only seen at 100 mg/kg. PB was administered in drinking water at 50, 100 and 1000 mg PB/l. Significant (P less than 0.05) induction of hepatic deethylation was seen at all dose levels, ranging from 2-fold at 50 mg/l to 5-fold at 1000 mg/l. Hepatic cytochrome P450 was also increased. No significant increase in intestinal deethylation was seen at any of the doses used.
mesh_terms: D015660:7-Alkoxycoumarin O-Dealkylase; D000818:Animals; D001571:Benzoflavones / Q000494:pharmacology*; D019363:Cytochrome P-450 CYP1A1; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis; D004790:Enzyme Induction / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology*; D007420:Intestine, Large / Q000201:enzymology*; D007421:Intestine, Small / Q000201:enzymology*; D008099:Liver / Q000201:enzymology*; D008297:Male; D008861:Microsomes / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000096:biosynthesis; D010088:Oxidoreductases / Q000096:biosynthesis; D010105:Oxygenases / Q000096:biosynthesis; D010634:Phenobarbital / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D019324:beta-Naphthoflavone
chemical_list: D001571:Benzoflavones; D005419:Flavonoids; D019324:beta-Naphthoflavone; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; D010105:Oxygenases; D015660:7-Alkoxycoumarin O-Dealkylase; D019363:Cytochrome P-450 CYP1A1; D010634:Phenobarbital