2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced ethoxyresorufin-O-deethylase (EROD) and aldehyde dehydrogenase (ALDH3) activities in the brain and liver

Unkila, Mikko; Pohjanvirta, Raimo; Honkakoski, Paavo; Törrönen, Riitta; Tuomisto, Jouko

doi:10.1016/0006-2952(93)90551-7

Cited by 34 publications

(14 citation statements)

References 26 publications

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“…EROD activity (picomoles resorufin formed/milligram microsomal protein per minute) in liver microsomes was 50±4 and 3180±420 in control and b-NF-treated rats, respectively (data not displayed). These values are within the range of the activities in the liver and brain of rats reported in other studies (Perrin et al 1990;Unkila et al 1993).…”

Section: Microsomal Cyp1a1 and Cyp1a2 Protein Levels In Cerebellum Frsupporting

confidence: 80%

Constitutive and inducible levels of CYP1A1 and CYP1A2 in rat cerebral cortex and cerebellum

Iba

Storch

Ghosal

et al. 2003

Archives of Toxicology

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We examined the constitutive and inducible levels of microsomal cytochromes P450 1A1 and 1A2 (CYP1A) in rat cerebral cortex and cerebellum at the level of proteins by western blot analysis, and by catalytic activities via ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-demethylase (MROD). In the cerebral cortex, cytochrome P450 1A1 (CYP1A1) protein was more abundant than cytochrome P450 1A2 (CYP1A2) protein. Treatment with beta-naphthoflavone (beta-NF) caused a slight decrease in the level of the former but induced the latter 5.8-fold. In the cerebellum, in contrast to the cerebral cortex, CYP1A1 protein was less abundant than CYP1A2 protein in untreated rats, and while beta-NF treatment caused a 3.3-fold induction of CYP1A1 protein, it resulted in a 10-fold decrease in CYP1A2 protein. The CYP1A-preferential activity EROD was 2.3-fold higher in the cerebellum than in the cerebral cortex, and was induced 1.5-fold and 1.9-fold in the cerebellum and cerebral cortex, respectively, by beta-NF treatment. The CYP1A2-preferential activity MROD was 3-fold higher in the cerebellum than in the cerebral cortex, and was repressed 2.2-fold in the cerebellum but induced 3.7-fold in the cerebral cortex following beta-NF treatment. The results show that CYP1A1 and CYP1A2 proteins and catalytic activities are constitutively expressed in brain but are differentially inducible in the rat cerebral cortex and cerebellum.

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Section: Microsomal Cyp1a1 and Cyp1a2 Protein Levels In Cerebellum Frsupporting

confidence: 80%

Constitutive and inducible levels of CYP1A1 and CYP1A2 in rat cerebral cortex and cerebellum

Iba

Storch

Ghosal

et al. 2003

Archives of Toxicology

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“…The ability of this enzyme to generate oxygen free radicals as products of its catalytic cycle has been documented (Martinez-Cayuela, 1995). Dose-dependent increases in the activity of aldehyde dehydrogenase in brain tissue of rats are observed following in vivo treatment with TCDD at doses ranging from 5 to 50 fig/kg body wt (Unkila et al, 1993). This induction may contribute to overproduction of reactive oxygen species in brain tissues in response to TCDD administration.…”

Section: Discussionmentioning

confidence: 98%

Induction of Oxidative Stress in Brain Tissues of Mice after Subchronic Exposure to 2,3,7,8-Tetrachlorodibenzo-p-dioxin

Hassoun

Wilt

DeVito

et al. 1998

Toxicological Sciences

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“…Several studies on mammalian brain CYP have reported that the olfactory bulb contains higher CYP-dependent activities than other brain parts (Das et al 1982;Iscan et al 1990). Unkila et al (1993) showed that the EROD activity in the rat olfactory bulbs was highly inducible by TCDD. CYP 1Al/1A2 has been located to the tufted cells in the rat olfactory bulb by immunohistochemical methods (Kohler et al 1988).…”

Section: P2 P3mentioning

confidence: 99%

“…Immunohistochemical studies also suggested that CYP 1A or immunologically similar forms are constitutively expressed in rat brain (Kohler et al 1988). Moreover, treatment of rats with polyaromatic hydrocarbon (PAH)-type inducers increased brain 7-ethoxyresorufin-Odeethylase (EROD) activity, which indicate induction of a CYP 1A form (Walther et al 1987;Unkila et al 1993). The brain may thus be an important target organ for environmental pollutants, contributing to neurotoxicological or endocrinological effects of such compounds.…”

Section: Introductionmentioning

confidence: 99%

Distribution and induction of cytochrome P450 1A1 in the rainbow trout brain

Andersson

Goksøyr

1994

Fish Physiol Biochem

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Cytochrome P450 (CYP) 1A1 participates in the activation as well as detoxification of environmental pollutants such as aromatic hydrocarbons. This CYP form is also efficiently induced by aromatic hydrocarbons. The presence of CYP 1A1 in the brain might thus be of physiological and toxicological importance. In the present investigation on rainbow trout, the distribution of 7-ethoxyresorufin-O-deethylase (EROD) activity, a cytochrome CYP 1A1 catalyzed reaction, was measured in whole tissue homogenates from brain parts. In control fish, a relatively high activity was found in the rainbow trout olfactory bulb compared to the other brain parts. Although an EROD induction (3 to 7-fold) by β-naphthoflavone (BNF) was recorded in all brain parts from the rainbow trout, the highest induced activity was measured in the olfactory bulbs. To ascertain the distribution of EROD activity in cells, whole brain tissue was subfractionated by differential centrifugation. The fractionation scheme separated mitochondria (P2 fraction) and microsomes (P3 fraction) as determined by marker enzymes and electron microscopy. In control rainbow trout, a low EROD activity could be measured in the P2 fraction. BNF induced the EROD activity in both P2 and P3 fractions. Western blotting showed the induction by BNF of a protein band in the P2 and P3 fractions with a molecular mass around 58,000 when highly specific anti-cod CYP 1A1 antibodies were used. ELISA measurements confirmed the induction of CYP 1A1 protein in the rainbow trout brain subcellular fractions.

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2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced ethoxyresorufin-O-deethylase (EROD) and aldehyde dehydrogenase (ALDH3) activities in the brain and liver

Cited by 34 publications

References 26 publications

Constitutive and inducible levels of CYP1A1 and CYP1A2 in rat cerebral cortex and cerebellum

Constitutive and inducible levels of CYP1A1 and CYP1A2 in rat cerebral cortex and cerebellum

Induction of Oxidative Stress in Brain Tissues of Mice after Subchronic Exposure to 2,3,7,8-Tetrachlorodibenzo-p-dioxin

Distribution and induction of cytochrome P450 1A1 in the rainbow trout brain

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