Induction of N-nitrosodimethylamine metabolism in liver and lung by in vivo pyridine treatments of rabbits

Arinc, E
Adalı, Orhan
Gencler-Ozkan, AM
N-Nitrosodimethylamine is a procarcinogen that is activated by cytochrome P450 dependent N-nitrosodimethylamine N-demethylase to labile alpha-carbon hydroxylated products further resulting in active methylating agents. In vivo intraperitoneal administration of pyridine to rabbits significantly increased N-nitrosodimethylamine N-demethylase activity by 6.9- and 5.2-fold in liver and lung microsomes, respectively. Although, p-nitrophenol hydroxylase and aniline 4-hydroxylase activities were markedly enhanced by pyridine treatment in liver about 4.4- and 5.8-fold, respectively, no change was observed in the activities of these enzymes in lung microsomes. Pyridine treatment also elevated P450 contents of liver and lung by 2.04- and 1.4-fold, respectively. SDS-PAGE of pyridine-induced liver microsomes revealed a protein band of enhanced intensity having M-r of 51,000 migrating in the region of cytochrome P4502E1. The results obtained in this study demonstrated for the first time, a significant 5.2-fold induction of NDMA N-demethylase activity in the rabbit lung over the controls. Pyridine is readily absorbed by inhalation and is a constituent of tobacco and tobacco smoke. Thus induction of NDMA N-demethylase suggests that in the lung, as in the liver, pyridine may stimulate the metabolic activation of this nitrosamine significantly.


Mechanism of Inhibition of CYP1A1 and Glutathione S-Transferase Activities in Fish Liver by Quercetin, Resveratrol, Naringenin, Hesperidin, and Rutin
Arinc, Emel; Yilmaz, Duygu; BOZCAARMUTLU, AZRA (2015-01-02)
Quercetin, resveratrol, naringenin, hesperidin, and rutin are phenolic compounds/flavonoids that may have roles in the reduction of cancer susceptibility. In this study, in vitro modulatory effects of them were studied on liver CYP1A1 associated 7-ethoxyresorufin-O-deethylase (EROD) activity and glutathione S-transferase (GST) activity of leaping mullet (Liza saliens). All of the phenolic compounds/flavonoids used exerted an inhibitory effect on both EROD and GST activities of fish. Quercetin, resveratrol, ...
Modulation of human flavin-containing monooxygenase 3 activity by tricyclic antidepressants and other agents: Importance of residue 428
Adalı, Orhan; Philpot, RM (Elsevier BV, 1998-10-01)
Human flavin-containing monooxygenase 3 (FMO3) is subject to modulation by tricyclic antidepressants and other agents. Imipramine activates FMO3-catalyzed metabolism of methimazole at all substrate concentrations tested. This distinguishes FMO3 from rabbit FMO1 and FMO2, which are activated at high substrate concentration and inhibited at low substrate concentration, and pig FMO1, which is inhibited at all substrate concentrations. The response of FMO3 is also unique in that chlorpromazine is markedly more ...
KARAKURT, SERDAR; Adalı, Orhan (2011-01-01)
Glutathione S-transferase and NAD(P)H: quinone oxidoreductase 1 enzymes have important roles in detoxification and also activation of a wide variety of chemicals. Moreover, resistance of tumor cells against chemotherapeutic agents has been implicated in GST activities. The aim of this study was to investigate the effect of polyphenolic compound tannic acid on rabbit liver and kidney glutathione S-transferase and NAD(P)H: quinone oxidoreductase 1 enzyme activities. Tannic acid was found to be a potent inhibi...
Selective oxidation and reduction reactions with cofactor regeneration mediated by galactitol-, lactate-, and formate dehydrogenases immobilized on magnetic nanoparticles
Demir, Ayhan Sıtkı; Talpur, Farah N.; Sopaci, S. Betul; Kohring, Gert-W; ÇELİK, AYHAN (Elsevier BV, 2011-04-10)
Rapid immobilization with the one-pot purification of galactitol dehydrogenase (GatDH) and formate dehydrogenase (FDH) is achieved by using iminodiacetic acid (IDA) with chelated Co2+ modified magnetic nanoparticles as a carrier. Lactate dehydrogenase (LDH) from recombinant Escherichia coli and FDH commencing Candida methylica were used as an auxiliary enzyme for the regeneration of NADH/NAD(+) with a representative synthesis of (S)-1,2-propanediol and L-tagatose starting from hydroxyacetone and galactitol....
GOKER, H; ERTAN, R; AKGUN, H; YULUG, N (Wiley, 1991-05-01)
Synthesis and antifungal evaluation of 5-ethoxycarbonyl-2-(substituted-benzyl or phenoxymethyl)benzimidazoles are reported. Structures of the compounds were elucidated with IR-, H-1-NMR-, C-13-NMR-, mass-spectra and elemental analysis. Preliminary results show that none of the synthesized benzimidazole derivatives has antifungal activity at the concentration of 100-mu-g/ml against Candida parapsilosis, Candida stellatoidea, and Candida pseudotropicalis.
Citation Formats
E. Arinc, O. Adalı, and A. Gencler-Ozkan, “Induction of N-nitrosodimethylamine metabolism in liver and lung by in vivo pyridine treatments of rabbits,” ARCHIVES OF TOXICOLOGY, pp. 329–334, 2000, Accessed: 00, 2020. [Online]. Available: