O Lúpus Eritematoso Sistêmico (LES) é uma doença inflamatória crônica autoimune que apresenta uma ampla variedade de manifestações clínicas e anormalidades imunológicas, afetando principalmente mulheres. É caracterizado pela perturbação da homeostase imunológica, que envolve a indução e produção de autoanticorpos, bem como pela formação e deposição de complexos imunes, que conduzem a uma intensa resposta inflamatória e dano tecidual. Há evidências de que fatores imunológicos, ambientais, hormonais e genéticos estão implicados na patogênese da doença. Genes e proteínas envolvidas na metabolização/detoxificação de xenobióticos são frequentemente utilizados como marcadores de susceptibilidade para o desenvolvimento de doenças, cuja etiologia está relacionada à exposição a fatores de risco ambientais. Enzimas do Citocromo P450 (CYP) são as principais responsáveis pela fase I de detoxificação, na qual ativam o xenobiótico, tornando-o mais eletrofílico e, desta forma, mais reativo. As Glutationa S-transferases (GST) são enzimas detoxificantes de fase II e normalmente conjugam a glutationa reduzida com uma variedade de compostos eletrofílicos, como espécies reativas de oxigênio, facilitando a excreção de produtos tóxicos. Polimorfismos nos genes CYP e GST são capazes de alterar a expressão e a atividade catalítica das enzimas, sendo responsáveis por diferenças interindividuais quanto à capacidade de biotransformação de xenobióticos. O objetivo do nosso trabalho foi avaliar a influência de três polimorfismos GST (GSTM1 nulo, GSTT1 nulo, e GSTP1*Val) e dois polimorfismos CYP (CYP1A1*2C e CYP2E1*5B) na predisposição ao LES em uma amostra de 370 pacientes com LES e 329 doadores de sangue saudáveis provenientes da região sul do Brasil. Os polimorfismos CYP foram genotipados por PCR-RFLP, enquanto que os polimorfismos GST foram genotipados por PCR multiplex (GSTM1 nulo, GSTT1 nulo) e PCR-RFLP para GSTP1. As freqüências alélicas e genotípicas foram comparadas entre pacientes e controles usando o teste de Qui-Quadrado ou o teste Exato de Fisher. As análises foram realizadas subdividindo os indivíduos de acordo com sua origem étnica. Entre os indivíduos Euro-descendentes, observou-se uma menor freqüência de genótipos heterozigotos GSTP1*Val em pacientes com LES em comparação aos controles (p=0,0047; OR 0,63 CI 95% 0,43 – 0,93 em relação a GSTP1*Ile/Ile e OR 0,49 CI 95% 0,26 – 0,92 em relação a GSTP1*Val/Val). No grupo Afro-descendente, houve tendência a uma maior freqüência do alelo GSTP1*Val em pacientes quando comparados aos controles (p=0,061). O alelo CYP2E1*5B foi significativamente mais freqüente nos pacientes do que em controles (p=0,038; OR 2,69 CI 95% 1,00 – 8,42). Não foi observada qualquer implicação clínica dos polimorfismos CYP e GST nos pacientes com LES. Nossos dados sugerem um papel protetor do genótipo heterozigoto GSTP1*105Ile/Val em Euro-descendentes e uma possível influência do alelo CYP2E1*5B na susceptibilidade ao LES entre Afro-descendentes. / Systemic lupus erythematosus (SLE) is an autoimmune chronic inflammatory disease that presents a variety of clinical manifestations and immunological abnormalities, particularly affecting women. It is characterized by disruption of immunologic homeostasis, which results in the induction and production of autoantibodies, as well as the formation and deposition of immune complexes, leading to an intense inflammatory response and tissue damage. There is evidence that immunological, environmental, hormonal and genetic factors are involved in the pathogenesis of the disease. Genes and proteins involved in metabolism/detoxification of xenobiotics are often used as markers of susceptibility to the development of diseases whose etiology is related to exposure to environmental risk factors. Cytochrome P450 (CYP) enzymes are primarily responsible for phase I detoxification, in which activate the xenobiotic, making it more electrophilic and thus more reactive. The Glutathione S-transferases (GST) are phase II detoxifying enzymes and usually conjugate reduced glutathione with a variety of electrophilic compounds, such as reactive oxygen species, facilitating the excretion of toxic products. Polymorphisms in the CYP and GST genes can alter the expression and catalytic activity of enzymes, being responsible for interindividual differences regarding the capacity of xenobiotics biotransformation. The aim of our study was to evaluate the influence of three GST polymorphisms (GSTM1 null, GSTT1 null and GSTP1*Val) and two CYP polymorphisms (CYP1A1*2C and CYP2E1*5B) in SLE predisposition in a sample of 370 SLE patients and 329 healthy blood donors, both from southern Brazil. The CYP polymorphisms were genotyped by PCR-RFLP, while the GST polymorphisms were genotyped by multiplex PCR and PCR-RFLP for GSTP1. Allelic and genotypic frequencies were compared between patients and controls using the Chi-square test or Fisher´s exact test. Analyses were performed subdividing the individuals according to their ethnic origin. Among European-derived individuals, it was observed a lower frequency of GSTP1*Val heterozygous genotypes in SLE patients compared to controls (p = 0.0047; OR 0.63 CI 95% 0.43 - 0.93 in relation to GSTP1*Ile/Ile) and (OR 0.49 95% CI 0.26 - 0.92 in relation to GSTP1*Val/Val). In African-derived group, there was a trend to a higher frequency of GSTP1*Val allele in patients when compared to controls (p=0.061). The CYP2E1*5B allele was significantly more frequent in patients than controls (p=0.038, OR 2.69 95% CI 1.00 - 8.42). We did not observe any clinical implication of the CYP and GST polymorphisms in patients with SLE. Our data suggest a protective role of the GSTP1*105Ile/Val heterozygous genotype in European-derived and a possible influence of the CYP2E1*5B allele in SLE susceptibility among African-derived.

Tacrolimus (TAC) é um fármaco imunossupressor muito utilizado na prevenção de rejeição aguda após o transplante de órgãos. Essa droga apresenta um índice terapêutico muito baixo e grande variabilidade intra e interindividual, sendo necessário programas de monitorização terapêutica para se otimizar a eficácia e limitar a toxicidade. O TAC é um fármaco substrato do CYP3A5 e transportado pela proteína de efluxo PGP e acredita-se que o polimorfismos genéticos (SNPs) destas proteínas estejam relacionados a alta variabilidade farmacocinética desta droga. Neste estudo, investigamos a influência dos polimorfismos destas proteínas sobre alguns parâmetros farmacocinéticos do TAC e também, na incidência de lesões renais e rejeição em receptores de transplante renal. Pacientes recebendo TAC a no mínimo 12 meses (n=108) foram genotipados (PCR real time) para os polimorfismos do CYP3A5*3 (rs776746) e do gene ABCB1 1236C>T (rs1128503), 2677G>T/A (rs2032582) e 3435C>T (rs1045642). Dados da concentração plasmática de vale (Co; ng/mL), dose diária normalizada (mg/dia por Kg do paciente) e a concentração plasmática do fármaco normalizada pela dose ingerida (Co/dose, ng/mL por mg/dia por kg do paciente) de TAC foram obtidos dos prontuários médicos ao longo de três anos após o transplante renal. O desfecho clínico foi analisado avaliando-se a curva de sobrevida o enxerto, a função renal obtida pelo clearance de creatinina (Equação de Cockroft-Gault), e desenvolvimento de lesões renais e rejeição aguda e crônica com diagnósticos estabelecidos mediante suspeita clínica e confirmados pela avaliação das biópsias quanto a presença de necrose tubular aguda (NTA) e nefropatia crônica do enxerto (NFC) de acordo com a classificação de BANFF 07. Os haplótipos do gene ABCB1 foram inferidos estatisticamente utilizando o software PHASE (version 2.1). Diferenças foram consideradas significativas quando p<0,05. Não observamos desvios em relação ao esperado pelo equilíbrio de Hardy-Weinberg em nossa população para nenhum dos genes estudados. Frequências alélicas destes polimorfismos (6986G 74%; 1236C 60%; 3435C 59% and 2677G 64%) e haplótipos (49% 2677G-3435C-1236C e 31% 2677T-3435T-1236T) foram consistentes com outros estudos realizados na população brasileira. Indivíduos portadores de ao menos um alelo *1 do gene CYP3A5 necessitavam de maiores doses de TAC para obter níveis plasmáticos semelhantes aos dos indivíduos homozigotos para o alelo *3 (0,09 ± 0,03 vs. 0,06 ± 0,03; mg/dia/kg; p<0,001). Ao final do primeiro ano de transplante pacientes CYP*3/*3 apresentavam praticamente o dobro da razão Co/dose quando comparados com os pacientes CYP*1/*1 (144,60 ± 67,29 vs. 70,44 ± 56,05 ng*mL-1 /mg*kg- 1 /dia; p<0,001). Observou-se semelhante em relação quando indivíduos portadores dos alelos e haplótipo variante da PGP foram avaliados. Não encontramos associações significativas entre os genótipos e a sobrevida do enxerto ou clearance de creatinina. No entanto, observamos que os pacientes portadores do haplótipo GCC apresentaram maior incidência de desenvolvimento de NFC. Este estudo confirma o efeito dos polimorfismos do CYP3A5 e, em menor grau da PGP na farmacocinética do TAC. No entanto, não encontramos associações entre esses polimorfismos e desfechos clínicos significantes, sugerindo que a genotipagem para o CYP3A5 ou ABCB1 ainda não deva ser incorporada na prática clínica como uma ferramenta para o manejo de transplante renal. / Tacrolimus (TAC) is widely used to prevent acute rejection following solid-organ transplantation. This drug is characterized by a narrow therapeutic index and drug monitoring programs are required both to optimize efficacy and to limit toxicity. TAC is known to be substrate of cytochrome P450 (CYP) 3A5 and P-glycoprotein (PGP/ABCB) and its been suggested that genetic polymorphisms (SNPs) of these proteins are highly associated with variations in TAC pharmacokinetics. We investigated the influence of polymorphisms of CYP3A5 and ABCB1 gene on the pharmacokinetic parameters (PK) of TAC and on the incidence of kidney injuries and allograft rejection (AR) in renal transplant recipients. Patients receiving TAC for at least 12 months (n=108) were genotyped (real-time PCR) for CYP3A5*3 (rs776746) and for ABCB1 1236C>T (rs1128503), 2677G>T/A (rs2032582) and 3435C>T (rs1045642) polymorphisms. TAC predose concentration (Co; ng/mL), TAC daily dose (mg/day per kg body weight) and dose-normalized predose concentrations (Co/dose; ng/mL per mg/day per kg body weight) were retrieved from medical records up to 03 years after transplantation. Clinical outcomes were analyzed evaluating renal function in terms of creatinine clearance ( Cockroft-Gault equation) and allograft survival. Kidney injuries and AR diagnostics were established by clinical suspicion and in presence of histological findings in renal biopsies according to the 2007 Banff classification. ABCB1 gene haplotypes were statistically inferred using PHASE software (version 2.1). No deviation from Hardy-Weinberg equilibrium was observed in our study population for the polymorphic loci examined in CYP3A5 and ABCB1. Allelic frequencies of these polymorphisms (6986G 74%; 1236C 60%; 3435C 60% and 2677G 65%) and haplotypes (49% 2677G-3435C-1236C and 30% 2677T- 3435T-1236T) were consistent with other studies in the Brazilian population. Individuals carrying at least one CYP3A5*1 allele required higher TAC dose to achieve similar TAC blood levels as the homozygous individuals for the *3 allele (0.09 ± 0.03 vs.0.06 ± 0.03, mg/day per kg body weight, p<0.001). The presence of the CYP3A5*1 allele was also associated with lower TAC Co/dose compared to CYP*3 homozygous (84.9 ± 43.2 vs. 144.6 ± 66.7 ng/mL per mg/day per kg body weight, p<0.001). Regarding ABCB1 polymorphisms, individuals homozygous for the variant allele of each individual SNP and for the haplotype (TTT) showed higher Co/dose ratio. No associations were found between SNPs or haplotypes and allograft survival or creatinine clearance. We did find, though, that patients carrying GCC haplotype had a higher incidence of chronic rejection. Our findings confirm the effect of CYP3A5 and, less pronounced of ABCB1 polymorphisms, on the TAC pharmacokinetic. On the other hand, we did not find any association between these polymorphisms and relevant clinical outcomes, suggesting that CYP3A5 and ABCB1 genotyping must not be incorporated as a useful clinical tool on the management of kidney transplantation.

As enzimas CYP2D6, CYP2C19 e CYP2C9 são responsáveis pelo metabolismo de aproximadamente metade dos 200 medicamentos mais prescritos nos EUA. Padronizamos ensaios de genotipagem baseados na discriminação alélica com o sistema TaqMan® em 198 indivíduos. Para o gene CYP2D6, os alelos *1 e *2 foram os mais freqüentes, seguidos pelos alelos *4, *41, *35, *17, *5, *10, *6, *29 e *9. Desenvolvemos também uma nova metodologia para a determinação do número de cópias do gene CYP2D6. Para o gene CYP2C19, o alelo *1 foi o mais frequente, seguido pelos alelos *17, *2 e *3. Nosso estudo foi o primeiro a determinar a freqüência alélica do gene CYP2C19 no Brasil. Para o gene CYP2C9, o alelo *1 foi o mais frequente, seguido pelos alelos *2 e *3. Desenvolvemos uma metodologia reprodutível e acessível para a genotipagem dos polimorfismos principais dos genes CYP2D6, CYP2C19 e CYP2C9. A identificação precoce de indivíduos suscetíveis a efeitos adversos, bem como de metabolizadores rápidos pode trazer grandes benefícios aos pacientes possibilitando assim uma medicina personalizada. / The enzymes CYP2D6, CYP2C19 and CYP2C9 metabolize approximately half of the 200 most prescribed drugs in the USA. We standardized genotyping tests based on allelic discrimination, using TaqMan® genotyping system in 198 samples. For the CYP2D6 gene, allele *1 and *2 were the most frequent, followed by alleles *4, *4, *35, *17, *5, *10, *6, *29 and *9. We have also developed a new methodology for determining the copy number variations of the CYP2D6 gene. For the CYP2C19 gene, the allele *1 was the most common, followed by the alleles *17, *2 and *3. In our concern, our study was the first to determine the allele frequency of the CYP2C19 gene in Brazil. For CYP2C9 gene, the allele *1 was the most common followed by the alleles *2 and *3. We developed a methodology reproducible and accessible for genotyping the most important polymorphisms of the genes CYP2D6, CYP2C19 and CYP2C9. The previous identification of individuals at risk to develop adverse drug reactions as well as ultrarapid-metabolizers may bring benefits to the patients, leading to a personalized therapy.

Cette thèse a été consacrée à l'évolution du transcriptome de Drosophila simulans, et à son rôledans l'adaptation et la spéciation. L'étude a comporté deux parties. La première utilisant des pucesà ADN pour comparer les transcriptomes de populations de D. simulans, de son espèce jumelleD. sechellia, et de leurs hybrides. La seconde basée sur la quantification des transcrits par séquen-çage haut débit pour comparer une population de la zone d'origine (Afrique), et une populationd'une zone récemment envahie (France métropolitaine). Ces analyses ont mis en évidence plusieursgroupes ou familles de gènes montrant des variations d'expression.Un résultat majeur est l'implication prépondérante de la famille des cytochromes P450 dansl'adaptation. Cette superfamille composée de 85 gènes chez D. simulans est notamment importantepour la détoxi_cation des xénobiotiques. L'expression de plusieurs gènes de cette famille estfortement réduite chez D. sechellia, probablement à cause de la spécialisation de cette espèce surla plante Morinda citrifolia (plante toxique pour les autres drosophiles). On peut s'attendre alorsà un relâchement des contraintes de sélection sur cette famille de gènes, dû à une forte réductionde la diversité des toxines auxquelles cette espèce est exposée.Ces gènes sont également impliqués dans la différenciation entre les populations de la zoneancestrale de D. simulans et les populations dérivées. La zone ancestrale, en Afrique de l'est etdans les îles de l'Océan Indien occidental, est encore peu anthropisée. A contrario, la plupartdes populations dérivées, comme ici notre population de la vallée du Rhône, sont exposées à descontraintes chimiques sous la forme de pesticides utilisés massivement sur les grandes cultures.Ces pesticides contraignent les populations dérivées à s'adapter, ce qui peut se réaliser par uneaugmentation de l'expression. Nous avons détecter une augmentation de l'expression de treizeP450, dont un gène très bien connu pour ses fonctions de détoxifcation : Cyp6g1. Ce gène montreune augmentation d'expression corrélée à une résistance aux pesticides et à l'insertion d'élémentstransposables en 5' ; ceci a été montré en détail chez D. melanogaster, et dans une moindre mesurechez D. simulans. Nous avons mis en évidence chez cette dernière espèce un nouvel évènementd'insertion.Nos résultats montrent également que d'autres familles de gènes impliqués dans les détoxi_-cations sont concernées par ces augmentations d'expression liées à l'anthropisation des milieux,notamment les Glutathion transfèrases (GST).Nous avons également examiné la plasticité d'expression liée au changement de ressource, enélevant une partie de nos populations sur la ressource d'origine (fruits), et une autre partie sur lemilieu axénique, milieu d'élevage standard de laboratoire (stérile). Les drosophiles élevées sur unmilieu "naturel" montrent une forte activation du système immunitaire, et notamment une forteinduction des gènes effecteurs de l'immunité innée, codant les peptides anti-microbiens. Cela estprobablement dû à la présence de microorganismes sur ce milieu (ici, la banane). En conclusion,cette thèse a révélé des familles de gènes fortement impliquées dans les différenciations d'expressionentre populations, espèces, et ressources, posant les jalons d'une meilleure compréhension desmécanismes d'adaptation du transcriptome.

<p>The present investigation is devoted to studies on porcine members of the cytochrome P450 4A (CYP4A) and CYP8B1 subfamilies, which are involved in bile acid biosynthesis and fatty acid metabolism. </p><p>Hyocholic acid is considered to fulfil the requirements for trihydroxy bile acids in the domestic pig (Sus scrofa) in the absence of cholic acid. Hyocholic acid is a 6α-hydroxylated product of chenodeoxycholic acid and the enzyme catalyzing the 6α-hydroxylation was cloned and found to be an atypical member of the CYP4A subfamily. The primary structure of this porcine enzyme, designated CYP4A21, shows about 75% overall sequence identity to members of the CYP4A subfamily expressed in rabbit and man. Divergent amino acids in a “signature sequence” in the active site of all hitherto known CYP4A fatty acid hydroxylases, were found to be important determinants for the 6α-hydroxylase activity of CYP4A21. </p><p>Two homologous CYP4A fatty acid hydroxylases, designated CYP4A24 and CYP4A25, expressed in pig liver and kidney were cloned. These two cDNAs encode proteins of 504 amino acids similar to CYP4A21. The overall identity between CYP4A24 and CYP4A25 is 97% compared to 94% identity to CYP4A21. Whereas CYP4A21 clearly deviates regarding structural features and catalytic activity it is more difficult to establish whether CYP4A24 and CYP4A25 are distinct enzymes or allelic variants of a single enzyme. </p><p>Cloning of the CYP4A21 gene showed a conserved organization compared to CYP4A genes in other species. A segment of the CYP4A24 gene was also cloned and comparison with the CYP4A21 gene revealed an extensive sequence identity also within introns as well as within the proximal promoter regions. This indicates that CYP4A21 and CYP4A fatty acid hydroxylases have a common origin and evolved by gene duplication. The CYP4A21 and CYP4A fatty acid hydroxylases, however, show distinct patterns of expression.</p><p>The key enzyme in cholic acid biosynthesis, CYP8B1, was markedly expressed in fetal pig liver compared to livers from young pigs. The opposite was shown for the expression of CYP4A21. An apparently conserved pig CYP8B1 gene was cloned and was intronless, similar to CYP8B1 genes from other species. The pig gene encoded a protein of 501 amino acids with 81% identity to CYP8B1 expressed in rabbit and man. Unlike other CYP8B1 genes, the pig promoter lacked a TATA-box. This might offer one explanation for the unusual expression pattern, which appears to be restricted to pig fetal life.</p>

<p>The human cytochrome P450 (CYP) family of monooxygenases is important for metabolism of drugs and endogenous compounds, e.g., vitamin A and D, cholesterol, steroids, fatty acids, and eicosanoids. This thesis describes the tissue distribution, catalytic properties, and possible function of CYP4F8 and CYP4F12. To this respect, methods for immunohistological analysis, and real-time PCR for analysis of their transcripts, were developed.</p><p>CYP4F8 was originally cloned from human seminal vesicles and proposed to catalyze 19-hydroxylation of prostaglandin H₂(PGH₂). This notion could now be supported, as cyclooxygenase-2, CYP4F8, and microsomal prostaglandin E synthase-1 were found to be co-localized in the epithelial linings of seminal vesicles. The three enzymes were also co-localized in the suprabasal layers of epidermis, suggesting a similar function of CYP4F8 in skin. Real-time PCR showed that CYP4F8 mRNA was more than 10-fold increased in psoriatic lesions compared to non-lesional skin. CYP4F8 immunoreactivity was also found in kidney cortex, transitional epithelium, corneal epithelium, and retina. Although transcripts of all three enzymes were detectable in retina, no co-localization was found. Pro inflammatory stimuli were found to increase CYP4F8 mRNA expression in cultured epidermal and corneal keratinocytes. In these tissues CYP4F8 might oxidize fatty acids or other eicosanoids than PGH₂.</p><p>CYP4F12 was originally cloned from the liver and small intestine, and found to oxidize arachidonic acid and two anti-histamines. Immunohistological studies showed that CYP4F12 immunoreactivity was present mainly in the gastrointestinal tract, e.g., stomach, ilium, and colon, but also in placenta. Although CYP4F8 and CYP4F12 have catalytic properties in common, there are important differences. CYP4F12 does not oxidize PGH₂, certain eicosanoids, and fatty acids. The prominent expression in the gut suggests that CYP4F12 might be involved in oxidation of drugs.</p>

The present investigation is devoted to studies on porcine members of the cytochrome P450 4A (CYP4A) and CYP8B1 subfamilies, which are involved in bile acid biosynthesis and fatty acid metabolism. Hyocholic acid is considered to fulfil the requirements for trihydroxy bile acids in the domestic pig (Sus scrofa) in the absence of cholic acid. Hyocholic acid is a 6α-hydroxylated product of chenodeoxycholic acid and the enzyme catalyzing the 6α-hydroxylation was cloned and found to be an atypical member of the CYP4A subfamily. The primary structure of this porcine enzyme, designated CYP4A21, shows about 75% overall sequence identity to members of the CYP4A subfamily expressed in rabbit and man. Divergent amino acids in a “signature sequence” in the active site of all hitherto known CYP4A fatty acid hydroxylases, were found to be important determinants for the 6α-hydroxylase activity of CYP4A21. Two homologous CYP4A fatty acid hydroxylases, designated CYP4A24 and CYP4A25, expressed in pig liver and kidney were cloned. These two cDNAs encode proteins of 504 amino acids similar to CYP4A21. The overall identity between CYP4A24 and CYP4A25 is 97% compared to 94% identity to CYP4A21. Whereas CYP4A21 clearly deviates regarding structural features and catalytic activity it is more difficult to establish whether CYP4A24 and CYP4A25 are distinct enzymes or allelic variants of a single enzyme. Cloning of the CYP4A21 gene showed a conserved organization compared to CYP4A genes in other species. A segment of the CYP4A24 gene was also cloned and comparison with the CYP4A21 gene revealed an extensive sequence identity also within introns as well as within the proximal promoter regions. This indicates that CYP4A21 and CYP4A fatty acid hydroxylases have a common origin and evolved by gene duplication. The CYP4A21 and CYP4A fatty acid hydroxylases, however, show distinct patterns of expression. The key enzyme in cholic acid biosynthesis, CYP8B1, was markedly expressed in fetal pig liver compared to livers from young pigs. The opposite was shown for the expression of CYP4A21. An apparently conserved pig CYP8B1 gene was cloned and was intronless, similar to CYP8B1 genes from other species. The pig gene encoded a protein of 501 amino acids with 81% identity to CYP8B1 expressed in rabbit and man. Unlike other CYP8B1 genes, the pig promoter lacked a TATA-box. This might offer one explanation for the unusual expression pattern, which appears to be restricted to pig fetal life.

The human cytochrome P450 (CYP) family of monooxygenases is important for metabolism of drugs and endogenous compounds, e.g., vitamin A and D, cholesterol, steroids, fatty acids, and eicosanoids. This thesis describes the tissue distribution, catalytic properties, and possible function of CYP4F8 and CYP4F12. To this respect, methods for immunohistological analysis, and real-time PCR for analysis of their transcripts, were developed. CYP4F8 was originally cloned from human seminal vesicles and proposed to catalyze 19-hydroxylation of prostaglandin H2 (PGH2). This notion could now be supported, as cyclooxygenase-2, CYP4F8, and microsomal prostaglandin E synthase-1 were found to be co-localized in the epithelial linings of seminal vesicles. The three enzymes were also co-localized in the suprabasal layers of epidermis, suggesting a similar function of CYP4F8 in skin. Real-time PCR showed that CYP4F8 mRNA was more than 10-fold increased in psoriatic lesions compared to non-lesional skin. CYP4F8 immunoreactivity was also found in kidney cortex, transitional epithelium, corneal epithelium, and retina. Although transcripts of all three enzymes were detectable in retina, no co-localization was found. Pro inflammatory stimuli were found to increase CYP4F8 mRNA expression in cultured epidermal and corneal keratinocytes. In these tissues CYP4F8 might oxidize fatty acids or other eicosanoids than PGH2. CYP4F12 was originally cloned from the liver and small intestine, and found to oxidize arachidonic acid and two anti-histamines. Immunohistological studies showed that CYP4F12 immunoreactivity was present mainly in the gastrointestinal tract, e.g., stomach, ilium, and colon, but also in placenta. Although CYP4F8 and CYP4F12 have catalytic properties in common, there are important differences. CYP4F12 does not oxidize PGH2, certain eicosanoids, and fatty acids. The prominent expression in the gut suggests that CYP4F12 might be involved in oxidation of drugs.

CYP2D6 metabolizes codeine to morphine, the active analgesic metabolite. Variation in brain CYP2D6 activity may affect brain morphine levels after codeine administration and thereby influence analgesia. We investigate the effect of inhibiting brain CYP2D on codeine-induced analgesia. METHODS: Rats received intracerebroventricular (i.c.v.) injections of CYP2D inhibitors or vehicle controls. Rats were then given subcutaneous codeine injections and analgesia was measured with the tail-flick test. Morphine and codeine concentrations in brain and plasma were measured. CYP2D activity in brain and liver were assessed in vitro. RESULTS: Compared to vehicle treatment, i.c.v. inhibitor treatments resulted in lower codeine-induced analgesia, lower morphine levels in brain but not in plasma after codeine injections, and lower CYP2D activity in brain membranes but not in liver microsomes. CONCLUSIONS: Inhibiting brain CYP2D reduces codeine’s metabolism to morphine, resulting in less analgesia. Variation in brain CYP2D6 activity may influence response to codeine and other CYP2D6 substrates.

CYP2D6 metabolizes codeine to morphine, the active analgesic metabolite. Variation in brain CYP2D6 activity may affect brain morphine levels after codeine administration and thereby influence analgesia. We investigate the effect of inhibiting brain CYP2D on codeine-induced analgesia. METHODS: Rats received intracerebroventricular (i.c.v.) injections of CYP2D inhibitors or vehicle controls. Rats were then given subcutaneous codeine injections and analgesia was measured with the tail-flick test. Morphine and codeine concentrations in brain and plasma were measured. CYP2D activity in brain and liver were assessed in vitro. RESULTS: Compared to vehicle treatment, i.c.v. inhibitor treatments resulted in lower codeine-induced analgesia, lower morphine levels in brain but not in plasma after codeine injections, and lower CYP2D activity in brain membranes but not in liver microsomes. CONCLUSIONS: Inhibiting brain CYP2D reduces codeine’s metabolism to morphine, resulting in less analgesia. Variation in brain CYP2D6 activity may influence response to codeine and other CYP2D6 substrates.