Pre-translational induction of pentoxyresorufin O-depentylase by pyridine.
Pentoxyresorufin O-depentylase activity, mainly associated with phenobarbital-inducible cytochrome P450IIB1 (designated CYP2B1), was increased after a single treatment of pyridine (250 mg/kg, i.p.), and further increased by repeated treatments for 5 days. The catalytic activity and immunoreactive protein of CYP2B recognized by polyclonal antibodies were significantly induced by a relatively high dose of pyridine (250 mg/kg, i.p.) while ethanol-inducible cytochrome P450IIE1 (CYP2E1) could be induced by a low dosage (25 mg/kg, i.p.). Unlike CYP2E1 induction without changing its mRNA level, the induction of CYP2B by pyridine was accompanied by an elevation of its mRNA, indicating a pre-translational activation of this enzyme. These results indicate that pyridine induces various isozymes of cytochromes P450 by different induction mechanisms.
Park
K S
KS
Laboratory of Metabolism and Molecular Biology, National Institute on Alcohol Abuse and Alcoholism, Rockville, MD 20852.
Sohn
D H
DH
Veech
R L
RL
Song
B J
BJ
D000815:Aniline Hydroxylase / Q000096:biosynthesis; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases; D019362:Cytochrome P-450 CYP2B1; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000235:genetics; D004790:Enzyme Induction / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D008297:Male; D010088:Oxidoreductases / Q000096:biosynthesis* / Q000235:genetics; D011725:Pyridines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D013250:Steroid Hydroxylases / Q000096:biosynthesis* / Q000235:genetics
D011725:Pyridines; D012333:RNA, Messenger; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D013250:Steroid Hydroxylases; D000815:Aniline Hydroxylase; D001189:Aryl Hydrocarbon Hydroxylases; D019362:Cytochrome P-450 CYP2B1; C025619:steroid 16-beta-hydroxylase; C023666:pyridine