Jacqueline Fung

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1. We have examined the catalytic activities (7-ethoxyresorufin O-deethylase [EROD] and 7-methoxyresorufin O-demethylase [MROD]), protein levels (Western blot analysis) and mRNA levels (Northern blot analysis) of cytochrome P4501A (CYP1A1 and CYP1A2) in the lung, liver and kidney following a single 2.5 mg/kg (15.4 micromol/kg) subcutaneous dose of nicotine(More)
In a previous study in which a single 2.5 mg/kg (15.4 micromol/kg) s. c. dose of nicotine effected a transient, lung-specific induction of cytochrome P-450 (CYP) 1A1 in the rat, a dose-response study and assessment of the lung specificity of the induction was limited by toxicity of the acute parenteral nicotine exposure. In the present study, we examined(More)
We compared pyridine and five of its metabolites in terms of (i) in vivo induction of CYP1A1 expression in the lung, kidney, and liver in the rat and (ii) in vitro binding to, and activation of, the aryl hydrocarbon receptor (AhR) in cytosol from rat liver or Hepa1c1c7 cells. Following a single 2.5 mmol/kg ip dose of either pyridine, 2-hydroxpyridine,(More)
Mainstream cigarette smoke (CS) and wood smoke (WS) were compared in terms of their pulmonary CYP1A1 inducibility. The inducibility was assessed in pulmonary microsomes from rats exposed to freshly generated CS or WS and in rat lung explants treated with extracts of CS or WS total particulate matter (TPM). Mutagenicity in Salmonella typhimurium TA98 and(More)
To determine the changes in heme metabolism associated with induction of cytochrome P450 expression by pyridine, we compared the time course of CYP1A expression with the time course of (i) expression of heme oxygenase-1 (HO-1) (EC 1.14.99.3), (ii) activity of delta-aminolevulinic acid synthetase (ALAS) (EC 2.3.1.37), and (iii) heme saturation of tryptophan(More)
The levels and activities of pulmonary microsomal CYP1A1 and CYP1A2 in 40-day-old male and female, and 120-day-old male offspring of pregnant rats treated with five weekly 0.1 microg/kg doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during gestation and lactation were compared with those in age-matched offspring of untreated dams. The(More)
Neurotoxicity of n-hexane is mediated by its metabolite 2,5-hexanedione (2,5-HD). Cytochrome P4502E1 (CYP2E1) has been suggested but not shown to be involved in the formation of the metabolite. An objective of the current study was to assess the essentiality of CYP2E1 for in vivo 2,5-HD formation from n-hexane. This was accomplished by comparing urinary(More)
The effect of the nicotinic receptor antagonist mecamylamine on nicotine-mediated convulsions and induction of pulmonary cytochrome P4501A1 (CYP1A1) was examined in the rat. Mecamylamine blocked the convulsions and inhibited CYP1A1 induction by nicotine at the level of CYP1A1 activity (93%) and protein (97%), but independently induced the enzyme also at the(More)
Studies showing the inhibition of isolated human topoisomerase II (topo II) by benzene metabolites such as hydroquinone, coupled with the recognition that benzene-induced acute myelogenous leukemia bears a resemblance to second cancers caused by topo II inhibitors such as etoposide, suggested that topo II inhibition by hydroquinone might induce leukemogenic(More)
The presence and inducibility of CYP1A1 in freshly isolated peripheral blood lymphocytes was examined in untreated rats and in rats pretreated with agents known to induce the enzyme in other tissues, as well as dexamethasone [CAS #50-02-2], which is not commonly associated with CYP1A1 induction. CYP1A1 but not CYP1A2 was detected by Western blot analysis of(More)