CYP isoenzymes
++ = mitochondrial
# = found in lung tissue
CYP1 2 subfamilies, 3 genes
(drug metabolism)
Isoenzyme Substrates Inducer Inhibitor Alleles Effects (alleles, interactions)
CYP1A1 # Chlorinated benzenes, coumarin activation! polycyclic hydrocarbons propofol, N2O *1 .. *4 (Unclear) placental 1A1 is induced by maternal tobacco smoking
Note that 1A1 is primarily extrahepatic (lung, placenta).
CYP1A2 #
(about 13% of liver CYP)
caffeine, TCA, erythromycin, haloperidol, theophylline, paracetamol, ropivacaine, propranolol, naproxen, tacrine, verapamil, ? propafenone metabolites, R-warfarin, coumarin activation (may also activate procarcinogens!) ! phenytoin, phenobarbitone, omeprazole, lansoprazole (but no significant interaction with theophyllin) , polycyclic hydrocarbons (smoking, charcoal-broiled meat!), rifampicin cimetidine >> ranitidine, fluvoxamine, grapefruit juice!
quinolones (ciprofloxacin, enoxacin > norfloxacin > ofloxacin > lomefloxacin)
*1A .. *1F, *2 *1C : decreased activity
*1F : more inducible
(thought to predispose to cancer)
several month delay in expression post-partum
CYP1B1 ? ? ? *1 .. *4, *11 .. *26 (unclear: may predispose to lung/breast carcinoma); congenital glaucoma!

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Last update 2000-1-22 Author