Inducibility of AhR-regulated CYP genes by beta-naphtoflavone in the liver, lung, kidney and heart of the pig

the presence and inducibility of CYP enzymes belonging to the family 1 (CYP 1A1, 1A2 and 1B!) and AhR have been studied in liver, lung, kidney and heart of control and beta-naphtoflavone (betaNF)-treated pigs. Segments of so far undescribed genes for porcine CYP 1A1, 1A2, 1B1 and Ahr were identified by RT_PCR and their sequences found to be higly homologous to those of the corresponding human genes. Our results demonstrated a differential expression and regulation of the AhR-mediated CYP genes in liver, lung, kidney and heart of the pig-naphtoflavone

Expression and activity of CYP 1A1 in different brain regions of control and beta-naphthoflavone-treated pigs

Expression and activity of CYP 1A1 in different brain regions of control and beta-naphthoflavone-treated pigs Gervasi, P.G.1, Chirulli, V.1, Zaghini, A.2, Vaccaro, E.3, Fiorio, R.3, Longo, V.3, Marvasi, L.2 1 Ins. Clinical Physiology, Metabolism, Pisa, Italy; 2 Bologna University, Patologia Veterinaria, Bologna, Italy; 3 Ins. Clinical Physiology, Metabolism, PISA, Italy The expression of the cytochrome P450 1A1 (CYP 1A1) and its related activities along with the Ah Receptor were investigated in liver and brain regions from control pigs and pigs treated with beta-naphthoflavone (30 mg/kg i.p. for 4 days). By RT-PCR analysis, using specific primers, it was demonstrated that mRNA of CYP 1A1 and AhR were expressed, although at different extent, in the liver, cortex, midbrain and cerebellum. However, the beta-naphthoflavone treatment had no apparent effect on expression pattern of this isoform, unlike liver, in any brain region. Then, some enzymatic activities (ethoxyresorufin O-deethylase and methoxyresorufin O-demethylase), known markers for the CYP 1A1/2, were studied in microsomes of liver and microsomes and mitochondria of cortex, midbrain and cerebellum from control and beta-naphthoflavone treated pigs. The enzymatic analysis revealed a presence of these activities about 3-4 times higher in mitochondria than in microsomes from all the brain regions examined. However, in contrast to the behaviour of the liver, beta-naphthoflavone treatment did not induce the cerebral activities. Despite the presence of AhR, the CYP1A1 in the pig brain was resistant to beta-naphthoflavone induction suggesting that there is a different regulation mechanism of this enzyme between the brain and liver

Expression and activity of CYP2E1 in circulating lymphocytes are not altered in diabetic individuals

Cytochrome P4502E1 (CYP2E1) plays an important role in ROS production thus favouring accelerated membrane lipid peroxidation. This isoform is strongly expressed in the liver but it can be also found in lymphocytes. As such, lymphocyte may provide a non-invasive accessible pool for screening CYP2E1 expression in man. We have, therefore, analysed CYP2E1 expression and activity in lymphocyte microsomes from 12 healthy controls, I I type I and 12 type 2 diabetic subjects by using Western blot and enzymatic activities. Immunoblotting did not show difference among CYP2E1 protein bands in controls, type I and type 2 diabetics. To assess CYP2E1 activity we used the 7-ethoxy4-trifluoromethylcoumarin (7-EFC), as a fluorescent substrate. The rate of deethylation of 7-EFC from controls did not differ from type I and type 2 diabetic subjects. The lack of any difference in CYP2E1 activity also was confirmed by the NADPH-dependent microsomal lipid peroxidation CCL4-induced assay showing similar peroxidation rates among controls and diabetic subjects. The results show that CYP2E1 expression/activity in lymphocytes is not enhanced in diabetes

Cytochrome P450 2J2 polymorphism in healthy Caucasians and those with diabetes mellitus

OBJECTIVE: Cytochrome P450 (CYP) 2J2 plays an important role in the biosynthesis of the biologically active cis-epoxyeicosatrienoic acids. An allelic variant named CYP2J2*6, which encodes an enzyme that is almost inactive in the metabolism of arachidonic acid, has recently been described. We investigated the frequency of the CYP2J2*6 variant in a Caucasian population and the relationship between this polymorphism and the development of micro- and macrovascular complications and hypertension in patients with type 1 or type 2 diabetes mellitus. METHODS: Genomic DNA was extracted from peripheral blood cells and the fragment containing the A/T single nucleotide polymorphism at position 25 661 in exon 8 of the CYP2J2 gene was amplified. The 532 bp amplified product was subsequently digested with Tsp509I and analyzed on 12% polyacrylamide gel electrophoresis. RESULTS: In the whole population, the frequency of the CYP2J2*6 allele was 0.0064 and the frequency of the CYP2J2*1 allele was 0.9936. Genotype distribution did not show significant differences between controls and patients with type 1 or type 2 diabetes. No homozygotes for CYP2J2*6 allele were found. No association was found between this allele and complications or hypertension in either type of diabetes. CONCLUSION: The CYP2J2*6 allele is rare in the Caucasian population, and no association is inferred between this allelic variant and diabetic complications