Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.5.2 (NQO1)
 6,196 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Microsomal and cytosolic drug-metabolizing enzyme activities of respiratory mucosa of male and female monkeys have been determined and compared to those of monkey liver. The results demonstrated that cytochrome P-450, NADPH-cytochrome P-450 reductase and some monooxygenase activities, especially ethoxycoumarin O-deethylase activity, were present in respiratory epithelium, although at lower levels than in liver. 2. Activities of non-oxidative enzymes--namely, epoxide hydrolase, UDP-glucuronyltransferase, glutathione S-transferase, DT-diaphorase, carbonyl reductase, benzaldehyde and propionaldehyde dehydrogenases--were also detected in respiratory tissue, some at higher levels than in liver. 3. The enzymic activities found in monkey nasal mucosa are not very similar to those in corresponding human tissue where, for example, UDP-glucuronyltransferase activity is not detectable. This indicates that monkey is not necessarily the best animal model for studies of the human upper respiratory tract.
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PMID:Drug-metabolizing enzymes in respiratory nasal mucosa and liver of cynomolgus monkey. 152 63

Study of oxidative and non-oxidative xenobiotic-metabolizing enzymes was undertaken in microsomal and cytosolic fractions of two human livers, 10 individual and several pooled samples of human respiratory nasal mucosa obtained by surgical operation of male and female patients affected by hypertrophy of the inferior turbinates. The purity of nasal microsomes was checked by electron microscopy and marker enzyme assay. The pooled samples of respiratory nasal epithelium contained, relative to liver, a low amount of cytochrome P450 (about 25 pmol/mg protein) and associated biotransformation activities, and a low level of other components of the mixed-function oxidase system such as cytochrome b5, NADH and NADPH-cytochrome c reductase however the NADH-cytochrome b5 reductase activity was comparable to that of liver. The P450-dependent monooxygenase activities such as ethoxycoumarin O-deethylase, ethoxyresorufin O-deethylase and the dimethylnitrosamine N-demethylase were found in nearly all nasal microsomal specimens. The aniline hydroxylase and the aminopyrine or hexamethylphosphoramide N-demethylases were detected only in the pooled nasal samples. With regard to the non-oxidative enzymes, the activities of glutathione S-transferase, DT-diaphorase, epoxide hydrolase, UDP-glucuronyl-transferase, carbonyl reductase, benzaldehyde and propionaldehyde dehydrogenases, were investigated both in the individual and pooled nasal tissues and livers. These activities were similar in nasal and liver tissue, except for UDP-glucuronyltransferase which was not detected in nasal mucosa. The present findings demonstrate that the respiratory section of human nose contains a wide array of oxidative and non-oxidative enzymes, which could play a crucial role in the bioactivation or detoxication in situ of inhaled xenobiotics.
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PMID:Xenobiotic-metabolizing enzymes in human respiratory nasal mucosa. 198 28

1. A study of xenobiotic-metabolizing enzyme activity of the olfactory and respiratory epithelium in the pig was undertaken. The results indicated that porcine olfactory mucosa contains all the components of the P450 system. 2. Monooxygenase activities were much higher in olfactory than in respiratory microsomes, and the olfactory activities dependent on CYP2A were higher than those in the liver. By contrast, the olfactory monooxygenases associated with CYP2E1 were poorly or not detected, whereas CYP2G1 and a protein immunorelated to CYP1A2 were expressed in the olfactory epithelium. 3. The activities of several non oxidative enzymes (glutathione S-transferase, UDP-glucuronyl transferase, epoxide hydrolase, DT-diaphorase, benzaldehyde and propionaldehyde dehydrogenases, and various esterases) were also determined in porcine tissues and were found to be higher in the olfactory than in the respiratory mucosa, but lower or similar to those in liver. 4. An unexpected finding was a higher activity of olfactory UDP-GT compared with that of liver when 1-naphtol but not p-hydroxybiphenyl (a good substrate for a specific olfactory UDP-GT(olf) in bovine and rat) was used as substrate, suggesting a porcine specific expression of UDP-GT isoforms. 5. The results taken together indicate that the olfactory epithelium of mammals has a similar cytochrome P450 profile with the CYP2A and CYP2G1 as dominant isoforms, whereas the olfactory non-oxidative enzymes appear qualitatively and quantitatively expressed to different extents.
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PMID:Xenobiotic-metabolizing enzymes in pig nasal and hepatic tissues. 984 40