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1.
Clin. biomed. res ; 39(4): 322-332, 2019.
Artigo em Inglês | LILACS | ID: biblio-1087323

RESUMO

O transtorno por uso de álcool (TUA) é influenciado pela genética, principalmente na metabolização do etanol. Os genes da álcool desidrogenase (ADH1B/ADH1C), enzima que transforma o etanol, apresentam SNPs (single nucleotide polymorphisms) que resultam em isoenzimas com diferentes taxas catalíticas. Estudos demonstraram que os SNPs Arg48His, Arg370Cys, Arg272Gln e Ile350Val contribuem para o TUA. Este artigo revisou os estudos que investigaram SNPs em ADH1B (Arg48His/Arg370Cys) e ADH1C (Arg272Gln/Ile350Val), bem como avaliou as variações nas frequências alélicas desses genes e a influência no TUA nas diferentes populações no mundo. As frequências alélicas dos polimorfismos foram comparadas pelos testes qui-quadrado de Pearson e exato de Fisher (p < 0,05). O SNP Arg48His confere proteção para o TUA em euroamericanos, latino-americanos, europeus, brasileiros, asiáticos e australianos. O SNP Arg370Cys confere proteção para o TUA em afrodescendentes. Os SNPs Arg272Gln e Ile350Val predispõem o TUA principalmente em europeus. Os SNPs Arg48His, Arg370Cys e Arg272Gln/Ile350Val foram mais frequentes em amostras de leste-asiáticos (69,7%), africanos (19,1%) e europeus (40,5%), respectivamente (p < 0,01). Os diferentes alelos dos genes ADH1B/ADH1C devido a SNPs têm uma importante contribuição no TUA. As frequências desses alelos variam conforme a população, resultando em diferentes efeitos no TUA. (AU)


Alcohol use disorder (AUD) is influenced by genetics, especially in the metabolism of ethanol. The ethanol dehydrogenase genes (ADH1B/ADH1C), which convert ethanol, have single nucleotide polymorphisms (SNPs) that result in isoenzymes with different catalytic rates. Studies have shown that the Arg48His, Arg370Cys, Arg272Gln, and Ile350Val SNPs contribute to AUD. This article reviewed the studies that investigated SNPs in ADH1B (Arg48His/Arg370Cys) and ADH1C (Arg272Gln/Ile350Val) and evaluated variations in the allele frequencies of these genes and their influence on AUD in different populations worldwide. The allele frequencies of the polymorphisms were compared by Pearson's chi-square and Fisher's exact tests (p < 0.05). The Arg48His SNP provides protection against AUD in Euro-Americans, Latin Americans, Europeans, Brazilians, Asians, and Australians. The Arg370Cys SNP provides protection against AUD in Afro-descendants. The Arg272Gln and Ile350Val SNPs predispose to AUD mainly in Europeans. The Arg48His, Arg370Cys, and Arg272Gln/Ile350Val SNPs were more frequent in East Asians (69.7%), Africans (19.1%), and Europeans (40.5%), respectively (p < 0.01). The different alleles of the ADH1B/ADH1C genes due to SNPs make an important contribution to AUD. The frequencies of these alleles vary among different populations, resulting in different effects on AUD..(AU)


Assuntos
Humanos , Transtornos Relacionados ao Uso de Álcool/genética , Polimorfismo de Nucleotídeo Único/genética , Álcool Desidrogenase/biossíntese , Transtornos Relacionados ao Uso de Álcool/epidemiologia , Etanol/efeitos adversos
2.
Biomédica (Bogotá) ; 38(4): 555-568, oct.-dic. 2018. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-983966

RESUMO

Introducción. Uno de los principales factores de riesgo del carcinoma hepatocelular es el consumo crónico de alcohol. En estudios en diferentes poblaciones, se sugiere que las variantes genéticas de las enzimas que participan en el metabolismo del alcohol, como la alcohol deshidrogenasa (ADH) y la citocromo P450 (CYP2E1), estarían asociadas con riesgo de enfermedades hepáticas terminales. Objetivo. Identificar y caracterizar las variantes alélicas de los genes ADH1B, ADH1C y CYP2E1 en pacientes colombianos con diagnóstico de cirrosis y carcinoma hepatocelular. Materiales y métodos. Se incluyeron muestras de pacientes atendidos entre el 2005 y el 2007, y entre el 2014 y el 2016, en la unidad de hepatología de un hospital de Medellín. La genotipificación de las muestras se hizo mediante reacción en cadena de la polimerasa (Polymerase Chain Reaction, PCR) con análisis de los polimorfismos en la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism, RFLP). Los resultados se compararon con los de dos grupos de control y con lo reportado en la base de datos del 1000 Genomes Project. Resultados. Se recolectaron 97 muestras de pacientes con diagnóstico de cirrosis y carcinoma hepatocelular. Los dos factores de riesgo más frecuentes fueron el consumo crónico de alcohol (18,6 %) y las colangiopatías (17,5 %). Los genotipos más frecuentes en la población de estudio fueron el ADH1B*1/1 (82 %), el ADH1C*1/1 (59 %) y el CYP2E1*C/C (84 %). Conclusiones. En este primer estudio de los polimorfismos en pacientes colombianos con diagnóstico de cirrosis y carcinoma hepatocelular, los genotipos más frecuentes fueron el ADH1B*1/1, el ADH1C*1/1 y el CYP2E1*C/C. No se observaron diferencias estadísticamente significativas en la frecuencia de los genotipos entre los casos y los controles. Se requieren estudios adicionales en población colombiana para evaluar el riesgo de la enfermedad hepática terminal por consumo crónico de alcohol y la asociación con los polimorfismos.


Introduction: One of the most important risk factors for hepatocellular carcinoma (HCC) is alcohol consumption: Studies in different populations suggest that the risk of liver disease could be associated with genetic variants of the enzymes involved in alcohol metabolism, such as alcohol dehydrogenase (ADH) and cytochrome P450 CYP2E1. Objective: To identify and characterize the allelic variants of ADH1B, ADH1C and CYP2E1 genes in Colombian patients with cirrhosis and/or HCC. Materials and methods: We included samples from patients attending the hepatology unit between 2005-2007 and 2014-2016 of a hospital in Medellin. Samples were genotyped using PCR-RFLP. We compared the results with two control groups and the 1000 Genomes Project database. Results: We collected 97 samples from patients with a diagnosis of cirrhosis and/or HCC. The two main risk factors were chronic alcohol consumption (18.6%) and cholangiopathies (17.5%). The most frequent genotypes in the study population were ADH1B*1/1 (82%), ADH1C*1/1 (59%), and CYP2E1*C/C (84%). Conclusions: This first study of polymorphisms in Colombian patients diagnosed with cirrhosis and/or HCC showed genotypes ADH1B*1/1, ADH1C*1/1 and CYP2E1*C/C as the most frequent. We found no significant differences in the genotype frequency between cases and controls. Further studies are necessary to explore the association between polymorphisms and the risk of end-stage liver disease from alcohol consumption.


Assuntos
Álcool Desidrogenase , Citocromo P-450 CYP2E1 , Carcinoma Hepatocelular/etiologia , Alelos , Genótipo , Cirrose Hepática/etiologia
3.
Electron. j. biotechnol ; 30: 118-124, nov. 2017. tab, ilus, graf
Artigo em Inglês | LILACS | ID: biblio-1021652

RESUMO

Background: Zymomonas mobilis is a Gram-negative microaerophilic bacterium with excellent ethanol-producing capabilities. The RecET recombination system provides an efficient tool for direct targeting of genes in the bacterial chromosome by PCR fragments. Results: The plasmids pSUZM2a-RecET and pSUZM2a-RecE588T were first developed to co-express RecE or RecE588 and RecT for homologous recombination. Thereafter, the PCR fragments of the tetracycline resistance marker gene flanked by 60 bp of adhA (alcohol dehydrogenase I) or adhB (alcohol dehydrogenase II) homologous sequences were electroporated directly into ZM4 cells harboring pSUZM2a-RecET or pSUZM2a-RecE588T. Both adhA and adhB were replaced by the tetracycline resistance gene in ZM4, yielding two mutant strains, Z. mobilis ZM4 ΔadhA and Z. mobilis ZM4 ΔadhB. These two mutants showed varying extent of reduction in ethanol production, biomass generation, and glucose metabolism. Furthermore, enzyme activity of alcohol dehydrogenase II in Z. mobilis ZM4 ΔadhB exhibited a significant reduction compared to that of wild-type ZM4. Conclusion: This approach provided a simple and useful method for introducing mutations and heterologous genes in the Z. mobilis genome.


Assuntos
Zymomonas/genética , Recombinação Homóloga , Plasmídeos , Recombinação Genética , Álcool Desidrogenase/metabolismo , Zymomonas/enzimologia , Eletroporação , Etanol/metabolismo , Técnicas de Inativação de Genes , Mutação
4.
Colomb. med ; 46(4): 176-182, Oct.-Dec. 2015. ilus
Artigo em Inglês | LILACS | ID: lil-774951

RESUMO

Objective: Identify and characterize polymorphisms of genes ADH2, ADH3, ALDH2 and CYP2E1 in a Colombian population residing in the city of Bogotá and determine its possible relationship to the alcoholism. Methods: ADH2, ADH3, ALDH2, and CYP2E1 genotypes a population of 148 individuals with non-problematic alcohol and 65 individuals with alcoholism were determined with TaqMan probes and PCR-RFLP. DNA was obtained from peripheral blood white cells. Results: Significant difference was found in family history of alcoholism and use of other psychoactive substances to compare alcoholics with controls. When allelic frequencies for each category (gender) were considered, frequency of A2 allele carriers in ADH2 was found higher in male patients than controls. In women, the relative frequency for c1 allele in CYP2E1 was lower in controls than alcoholics. The ALDH2 locus is monomorphic. No significant differences in allele distributions of the loci examined to compare two populations were observed, however when stratifying the same trend was found that these differences tended to be significant. Conclusions: This study allows us to conclude the positive association between family history of alcoholism and alcoholism suggesting that there is a favourable hereditary predisposition. Since substance dependence requires interaction of multiple genes, the combination of genotypes ADH2*2, CYP2E1*1 combined with genotype homozygous ALDH2*1 found in this study could be leading to the population to a potential risk to alcoholism.


Objetivo: Identificar y caracterizar los polimorfismos de los genes ADH2, ADH3, ALDH2 y CYP2E1 de colombianos residentes en la ciudad de Bogotá y determinar su posible relación con el alcoholismo. Métodos: Se determinaron los genotipos ADH2, ADH3, ALDH2 y CYP2E1 a una población de 148 individuos con un consumo no problemático de alcohol y 65 individuos con alcoholismo. La genotipificación se realizó con sondas TaqMan y PCR-RFLP, el ADN se obtuvo de células blancas de sangre periférica. Resultados: Se encontró diferencia significativa en la historia familiar de alcoholismo y el uso de otras sustancias psicoactivas. Cuando se consideraron frecuencias alélicas para cada categoría (género), la frecuencia de portadores del alelo A2 en ADH2 se encontró mayor en los pacientes masculinos que los controles. En las mujeres, la frecuencia relativa para el alelo C1 de CYP2E1 fue menor en controles que en alcohólicos. El locus ALDH2 es monomórfico. No se observaron diferencias significativas en las distribuciones alélicas de los loci examinadas al comparar las dos poblaciones, sin embargo al estratificar las mismas se encontró una tendencia a que esas diferencias fueran significativas. Conclusiones: Este estudio nos permite concluir la asociación positiva entre historia familiar de alcoholismo y el alcoholismo, lo que sugiere que existe una predisposición hereditaria favorable. Dado que la dependencia de sustancias requiere la interacción de múltiples genes como ADH2*2, CYP2E1*1 combinado con el genotipo homocigótico ALDH2*1 hallados en este estudio podría estar llevando a la población a un riesgo potencial hacia el alcoholismo.


Assuntos
Adulto , Feminino , Humanos , Masculino , Álcool Desidrogenase/genética , Alcoolismo/genética , Aldeído Desidrogenase/genética , /genética , Polimorfismo Genético , Estudos de Casos e Controles , Colômbia , Família , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Transtornos Relacionados ao Uso de Substâncias/genética
5.
Electron. j. biotechnol ; 14(4): 7-7, July 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-640502

RESUMO

The gene dhaT from Klebsiella pneumoniae encoding 1,3-propanediol oxidoreductase (PDOR) was de novo synthesized by splicing overlap extension polymerase chain reaction (SOE-PCR) primarily according to Escherichia coli’s codon usage, as well as mRNA secondary structure. After optimization, Codon Adaptation Index (CAI) value was improved from 0.75 to 0.83, meanwhile energy of mRNA secondary structure was increased from -400.1 to -86.8 kcal/mol. This synthetic DNA was under control by phage T7 promoter in the expression vector pET-15b and transformed into the E. coli BL21 (DE3) strain. Inducers such as isopropyl beta-D-thiogalactoside (IPTG) and lactose were compared by activity at different inducing time. The activity of PDOR after codon optimized was 385.4 +/- 3.6 U/mL, which was almost 5-fold higher than wild type (82.3 +/- 1.5 U/ml) under the flask culture at 25ºC for 10 hrs. Then his-tagged enzyme was separated by using Ni-IDA column. The favorite environment for enzyme activity was at 5°C and pH 10.0, PDOR showed a certainly stability in potassium carbonate buffer for 2 hrs at diverse temperatures, enzyme activity was significantly improved by Mn2+.


Assuntos
Álcool Desidrogenase , Códon/genética , Escherichia coli/genética , Propilenoglicóis , Adaptação Fisiológica , Escherichia coli/enzimologia , Expressão Gênica , Genes Bacterianos , RNA Mensageiro , Reação em Cadeia da Polimerase/métodos
6.
J. bras. psiquiatr ; 60(1): 7-10, 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-581564

RESUMO

OBJECTIVE: The aim of this study was to investigate the polymorphism Ile349Val of the enzyme alcohol dehydrogenase ADH1C gene among individuals with alcohol dependence syndrome (ADS) attending Alcoholics Anonymous (AA) meetings. METHODS: A total of 120 subjects residing in Rio de Janeiro city participated in this study. Subjects were divided into two groups: a group consisting of 54 individuals from the ADS group and 66 individuals that declared not having any alcohol dependence (control group). DNA was extracted from mouth epithelial cells by phenol-chloroform method and further submitted to amplification by polymerase chain reaction (PCR). RESULTS: Our results did not show differences between the genotypes of control individuals and ADS subjects. Nevertheless, we found increased rates of alcoholism in families of ADS subjects as compared to controls. CONCLUSIONS: Our results did not show any genotype difference on the ADH1C gene when control and AA genotypes are compared.


OBJETIVO: Investigar o polimorfismo Ile349Val do gene ADH1C da enzima álcool desidrogenase e a dependência de álcool em indivíduos frequentadores dos Alcoólicos Anônimos (AA). MÉTODOS: Um total de 120 pessoas residentes na cidade do Rio de Janeiro foi dividido em dois grupos: o primeiro foi formado por 54 pessoas com síndrome de dependência do álcool (SDA) pertencentes ao grupo dos AA. O segundo, com 66 pessoas, foi formado por indivíduos que descreveram não serem dependentes de álcool (grupo controle). O DNA foi extraído de células da mucosa oral utilizando-se a técnica do fenol-clorofórmio e posteriormente amplificado pela reação em cadeia pela polimerase (PCR). RESULTADOS: Nossos resultados não mostraram diferenças entre o genótipo dos indivíduos controle e aqueles do grupo SDA. A análise, entretanto, demonstrou uma significativa relação entre o grupo SDA e o histórico familiar de alcoolismo. CONCLUSÕES: Em nossos resultados não encontramos diferenças quanto ao genótipo ADH1C em indivíduos com SDA e controles.


Assuntos
Humanos , Masculino , Feminino , Álcool Desidrogenase , Transtornos Relacionados ao Uso de Álcool , Alcoolismo/genética , Alcoolismo/psicologia , Polimorfismo Genético , Brasil , Inquéritos e Questionários , Reação em Cadeia da Polimerase , Distribuição por Sexo
7.
Braz. j. med. biol. res ; 43(3): 257-261, Mar. 2010. tab
Artigo em Inglês | LILACS | ID: lil-539724

RESUMO

Alcohol dependence poses a serious medical and sociological problem. It is influenced by multiple environmental and genetic factors, which may determine differences in alcohol metabolism. Genetic polymorphism of the enzymes involved in alcohol metabolism is highly ethnically and race dependent. The purpose of this study was to investigate the differences, if present, in the allele and genotype frequency of alcohol dehydrogenase 1B (ADH1B), ADH1C and the microsomal ethanol-oxidizing system (MEOS/CYP2E1) between alcohol-dependent individuals and controls and also to determine if these genotypes cause a difference in the age at which the patients become alcohol dependent. The allele and genotype frequencies of ADH1B, ADH1C, and CYP2E1 were determined in 204 alcohol dependent men and 172 healthy volunteers who do not drink alcohol (control group). Genotyping was performed by PCR-RFLP methods on white cell DNA. ADH1B*1 (99.3 percent) and ADH1C*1 (62.5 percent) alleles and ADH1B*1/*1 (N = 201) and ADH1C*1/*1 (N = 85) genotypes were statistically more frequent among alcohol-dependent subjects than among controls (99.3 and 62.5 percent, N = 201 and 85 vs 94.5 and 40.7 percent, N = 153 and 32, respectively). Differences in the CYP2E1 allele and genotype distribution between groups were not significant. The persons with ADH1C*1/*1 and CYP2E1*c1/*c2 genotypes became alcohol dependent at a considerably younger age than the subjects with ADH1C*1/*2, ADH1C*2/*2 and CYP2E1*c1/*c1 genotypes (28.08, 25.67 years vs 36.0, 45.05, 34.45 years, respectively). In the Polish men examined, ADH1C*1 and ADH1B*1 alleles and ADH1C*1/*1 and ADH1B*1/*1 genotypes favor alcohol dependence. The ADH1B*2 allele may protect from alcohol dependence. However, subjects with ADH1C*1/*1 and CYP2E1*c1/*c2 genotypes become alcohol dependent at a considerably younger age than the subjects with ADH1C*1/*2, ADH1C*2/*2 and CYP2E1*c1/*c1 genotypes.


Assuntos
Adolescente , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Álcool Desidrogenase/genética , Alcoolismo/enzimologia , /genética , Polimorfismo Genético/genética , Fatores Etários , Alcoolismo/genética , Estudos de Casos e Controles , Predisposição Genética para Doença , Genótipo , Frequência do Gene/genética , Polônia , Adulto Jovem
8.
Genet. mol. biol ; 32(1): 177-185, 2009. graf, tab
Artigo em Inglês | LILACS | ID: lil-505766

RESUMO

The ADH (alcohol dehydrogenase) system is one of the earliest known models of molecular evolution, and is still the most studied in Drosophila. Herein, we studied this model in the genus Anastrepha (Diptera, Tephritidae). Due to the remarkable advantages it presents, it is possible to cross species with different Adh genotypes and with different phenotype traits related to ethanol tolerance. The two species studied here each have a different number of Adh gene copies, whereby crosses generate polymorphisms in gene number and in composition of the genetic background. We measured certain traits related to ethanol metabolism and tolerance. ADH specific enzyme activity presented gene by environment interactions, and the larval protein content showed an additive pattern of inheritance, whilst ADH enzyme activity per larva presented a complex behavior that may be explained by epistatic effects. Regression models suggest that there are heritable factors acting on ethanol tolerance, which may be related to enzymatic activity of the ADHs and to larval mass, although a pronounced environmental effect on ethanol tolerance was also observed. By using these data, we speculated on the mechanisms of ethanol tolerance and its inheritance as well as of associated traits.


Assuntos
Animais , Álcool Desidrogenase/metabolismo , Tolerância a Medicamentos , Dípteros/genética , Indução Enzimática , Etanol , Hibridização Genética , Fenótipo , Polimorfismo Genético , Interpretação Estatística de Dados
9.
Rev. Ciênc. Méd. Biol. (Impr.) ; 7(2): 163-168, maio-ago. 2008. ilus, tab
Artigo em Português | LILACS, BBO - Odontologia | ID: lil-530647

RESUMO

As principais enzimas responsáveis pelo metabolismo do álcool são a álcool desidrogenase (ADH) e aldeído desidrogenase (ALDH). EsSas enzimas estão presentes em várias formas e são codificadas por diferentes genes. Alguns desses genes apresentam polimorfismos, e as enzimas codificadas por eles podem apresentar diferenças quanto à eficiência metabólica em relação ao álcool e ao aldeído acético. EsSa variação tem se mostrado um fator que influencia a quantidade de álcool ingerido e o risco no aumento de abuso e dependência ao álcool. Neste trabalho, nós descrevemos um método que permite estudar o polimorfismo de um dos genes da enzima álcool desidrogenase, o gene ADH1C. O DNA foi isolado de doadores e o polimorfismo foi determinado pela reação em cadeia pela polimerase (PCR). Nossos resultados confirmam a viabilidade da técnica por nós descrita para o estudo do polimorfismo do gene ADH1C.


Assuntos
Humanos , Alcoolismo , Polimorfismo Genético , Álcool Desidrogenase
12.
Acta amaz ; 36(4): 413-418, out.-dez. 2006. ilus, graf
Artigo em Português | LILACS | ID: lil-448120

RESUMO

Himatanthus sucuuba é uma espécie que coloniza as várzeas na Amazônia Central. O objetivo desse trabalho foi estudar as estratégias de adaptação da planta ao alagamento prolongado dessas áreas. Para tanto, foram acompanhados a germinação das sementes e o desenvolvimento das plântulas, simulando as condições naturais de campo (seca e alagamento). A germinação foi realizada em dois substratos: areia+serragem (não-alagado), e em água (alagado). Durante 120 dias, as plântulas geradas foram submetidas a três tratamentos: controle (irrigação diária), submersão parcial (sistema radicular) e submersão total. Foram analisadas as alterações na morfologia das plântulas, na anatomia das raízes e a atividade da enzima álcool desidrogenase (ADH), nos tempos: 0, 15, 30, 60, 90 e 120 dias. Foi constatado que a espécie apresenta elevada taxa de germinação e produção de plântulas, ambas acima de 80 por cento, mesmo para sementes em água. Sob submersão parcial foram formadas lenticelas hipertrofiadas, raízes adventícias e aerênquima radicular. A atividade da ADH se manteve elevada até o 60° dia, com decréscimo após esse período. Plântulas sob submersão total perderam as folhas, não formaram raízes adventícias ou lenticelas, mas desenvolveram aerênquima. Estas plântulas apresentaram os maiores valores da ADH, que permaneceram altos até o término do experimento, indicando o desvio do metabolismo anaeróbico para produção de etanol como principal via para a manutenção da carga energética. Apesar de ter ocorrido a morte de algumas plântulas no tratamento de submersão total, o percentual de sobreviventes foi alto com 70 por cento ao final dos 120 dias de duração do período experimental. Desta maneira, as plântulas de H. sucuuba modulam morfo-fisiologicamente a tolerância ao alagamento em função do tempo de exposição ao estresse e altura da coluna de água.


Himatanthus sucuuba is a tree which colonizes the varzeas of Central Amazonia. The present work was carried out in order to analyze the adaptive strategies of the species to cope with the long periods of flooding common in the várzea. Seeds were accompanied from germination until the seedling stage, in experimental conditions simulating natural field conditions (terrestrial phase and flooding period). Germination was tested in two substrates: sand + sawdust (only irrigated), and in water (submergence). The seedlings produced were then subjected, for 120 days, to three treatments: control (daily irrigation), partial submersion (root system) and total submersion (whole seedling). Alterations in the morphology of seedlings and in root anatomy were examined, together with the activity of the enzyme alcohol dehydrogenase (ADH) 0, 15, 30, 60, 90, and 120 days after the start of the treatments. Irrespective of the flooding regime, germination rates and seedling formation were high, both above 80 percent. Under partial submersion, hypertrophic lenticels, adventitious roots and aerenchyma were formed in the roots while ADH activity remained high until the 60th day of flooding, declining afterwards. Seedlings under total submersion lost all leaves, did not form adventitious roots or lenticels, but developed aerenchyma. These seedlings showed the highest values of ADH, which remained high until the end of the experiment, indicating the diversion of the aerobic metabolism to the production of ethanol as the main pathway to maintain the energetic balance. Although some totally submersed seedlings died, 70 percent of them survived the 120 days of flooding. Seedlings of H. sucuuba modulate morpho-physiologically the tolerance to flooding according to the time of exposure to the stress and the height of the water column.


Assuntos
Álcool Desidrogenase , Germinação , Zoneamento de Áreas de Inundação , Apocynaceae , Anaerobiose
13.
Electron. j. biotechnol ; 7(1): 72-84, Apr. 2004. ilus, tab, graf
Artigo em Inglês | LILACS | ID: lil-363999

RESUMO

Lactobacillus rhamnosus, a facultative anaerobe, which produces L (+) lactic acid and ethanol under anaerobic conditions, is used in the present study. An adh- mutant of Lactobacillus rhamnosus MTCC 1408, was developed by chemical mutagenesis, which could produce pure L(+) lactic acid as the only product. Batch fermentation kinetics of the wild type and the mutant strain were studied in glucose-yeast extract medium under conditions of temperature 40ºC and pH 6.2 anaerobically. The biomass yield was similar in both wild type and mutant strains, however lactic acid yield increased by 6.6 percent. A chemically defined media was optimized for supplementation of succinate, acetate and citrate for better biomass formation using single variable optimisation. It was further optimised for varying concentrations of vitamins, amino acids and trace metals by response surface method. The batch biomass yield (0.1g/g) and lactic acid yield (0.88g/g) in the optimised chemically defined media were similar to those obtained in the glucose-yeast extract medium.


Assuntos
Ácido Láctico/biossíntese , Fermentação , Lacticaseibacillus rhamnosus/genética , Mutagênese , Álcool Desidrogenase , Reatores Biológicos , Concentração de Íons de Hidrogênio , Cinética , Lacticaseibacillus rhamnosus/fisiologia , Controle de Qualidade , Temperatura
14.
Rev. méd. Chile ; 130(6): 681-690, jun. 2002. tab, graf
Artigo em Inglês | LILACS | ID: lil-317502

RESUMO

Although the interaction between alcohol and the liver has been the subject of intensive investigation since many years, several uncertainties remain to be solved. Good examples of what we need to learn are: The real number of patients with alcohol-induced liver disease (AILD), the dose of alcohol "safe" for the liver, the genetic predisposition to the damage or, on the other side of the coin, protecting from the damage. Rather recently, however, part of these questions started to be clarified, thus permitting a better definition of the role of each of these factors in AILD. In parallel to the clinical approach to AILD, the unveiling of the molecular and biochemical mechanisms involved in AILD has progressed and proved to be important in both a better understanding of the disease and, more important, in a more rational treatment of these disorders. This review will focus on what we currently know of AILD in clinical, biochemical and molecular terms and what we need to address in the future


Assuntos
Humanos , Animais , Ratos , Etanol , Hepatopatias Alcoólicas/etiologia , Álcool Desidrogenase , Fator de Necrose Tumoral alfa , Etanol , Estresse Oxidativo , Hepatopatias Alcoólicas/genética
15.
Braz. j. med. biol. res ; 31(11): 1449-58, Nov. 1998. ilus, tab, graf
Artigo em Inglês | LILACS | ID: lil-224481

RESUMO

Karyological characteristics, i.e., diploid number, chromosome morphology and nucleolus organizer regions (NORs), biochemical characteristics, i.e., electrophoretic analysis of blood hemoglobin and the tissue enzymes lactate dehydrogenase (LDH), malate dehydrogenase (MDH), alcohol dehydrogenase (ADH), and phosphoglucose isomerase (PGI), and physiological characteristics, i.e., relative concentration of hemoglobin and intraerythrocytic concentrations of organic phosphates were analyzed for the species Callophysus macropterus collected from Marchantaria Island (white water system - Solimöes River) and Anavilhanas Archipelago (black water system - Negro River). Karyological and biochemical data did not reveal significant differences between specimens collected at the two sites. However, the relative distribution of hemoglobin bands I and III (I = 16.33 ñ 1.05 and III = 37.20 ñ 1.32 for Marchantaria specimens and I = 6.33 ñ 1.32 and III = 48.05 ñ 1.55 for Anavilhanas specimens) and levels of intraerythrocytic GTP (1.32 ñ 0.16 and 2.76 ñ 0.18 for Marchantaria and Anavilhanas specimens, respectively), but not ATP or total phosphate, were significantly different, indicating a physiological adaptation to the environmental conditions of these habitats. It is suggested that C. macropterus specimens from the two collecting sites belong to a single population, and that they adjusted some physiological characteristics to adapt to local environmental conditions.


Assuntos
Animais , Peixes/genética , Peixes/metabolismo , Água Doce , Adaptação Biológica , Álcool Desidrogenase/análise , Alelos , Encéfalo/enzimologia , Eletroforese , Olho/enzimologia , Peixes/fisiologia , Genótipo , Glucose-6-Fosfato Isomerase/análise , Hemoglobinas/análise , Isoenzimas/análise , L-Lactato Desidrogenase/análise , Fígado/enzimologia , Malato Desidrogenase/análise , Músculo Esquelético/enzimologia , Miocárdio/enzimologia , Fosfatos/sangue , América do Sul
16.
Med. interna Méx ; 14(4): 180-5, jul.-ago. 1998.
Artigo em Espanhol | LILACS | ID: lil-243169

RESUMO

El hígado es el órgano que en el humano principalmente metaboliza el etanol, pues posee tres sistemas que lo oxidan a acetaldehído que son: alcohol deshidrogenasa (ADH que se localiza en el citosol), catalasa (que se encuentran en las perixisomas), y citrocromo P-450 (que se ubica en el retículo endoplásmico liso conocido como sistema MEOS). Estos sistemas convierten al etanol en acetaldehído con la ayuda de las coenzimas NAD + y NADP +, mismas que se reducen hasta NADII y NADPII, respectivamente. El acetaldehído penetra en la mitocondría y se oxida a acetato por medio de la enzima aldehído deshidrogenasa (ALDH) y reduce una molécula de NAD + a NADH. Durante la ingestión aguda de etanol, la ADH es la principal enzima que metaboliza al etanol y participa en 85 por ciento durante la oxidación de éste, mientras que la catalasa y el sistema MEOS se encuentran inducidos y pueden llegar a metabolizar 40 por ciento del etanol ingerido. La oxidación de etanol hasta acetato produce equivalentes reductores (NADII y NADPH) en citosol y mitocondria, lo que ocasiona alteraciones en el metabolismo intermedio en los dos organitos intracelulares que, a su vez, son responsables de las alteraciones metabólicas que se encuentran el en hígado, en donde los sistemas de oxidación alternos de etanol se aumenta


Assuntos
Humanos , Álcool Desidrogenase , Alcoolismo/metabolismo , Etanol/metabolismo , Hepatopatias Alcoólicas/metabolismo , Fígado/fisiopatologia , Fígado/metabolismo
17.
Arch. med. res ; 28(4): 453-71, dec. 1997. ilus, tab
Artigo em Inglês | LILACS | ID: lil-225251

RESUMO

Ehtanol or wthyl alcohol is a molecule that, in mammals, is naturally present at low concentrations due to its production by gastrointestinal flora fermentation activity. However, it is remarkable that this metabolite, with a clearly minor role in regular vertebrate metabolism, can be oxidized into acetaldehyde through several ensymatic and non-enzymatic mechanisms, which comprise the activity of more than ten ensymes and isozymes, many of them broadly distributed in different specie and tissues. In correspondence, acetaldehyde can also be oxidized into acetate through several enzymatic pathways that involve about ten enzymes and isozymes which also have a broad distribution In this article, a complete review of the aforementioned metabolic pathways is elaborated. From this group, the participation and wide distribution of alcohol dehydrogenase and aldehyde dehydrogenase systems are emphasized. The mechanism of reaction, kinetic characteristics and physiological relevance are described, and finally, the possible physiological role of these enzymatic systems as responsible to synthesize or catabolize several endogenous metabolites that regulate growth, metabolism, differentiation and neuroendocrine function in mammals are discussed


Assuntos
Humanos , Animais , Acetaldeído/metabolismo , Álcool Desidrogenase/metabolismo , Aldeído Desidrogenase/metabolismo , Etanol/metabolismo , Mamíferos/metabolismo
19.
Braz. j. med. biol. res ; 29(5): 651-7, May 1996. tab
Artigo em Inglês | LILACS | ID: lil-182551

RESUMO

Alcohol elimination was studied in rats of different ages, reproductive states and nutritional deprivation, with the following results: 1) blood levels of ethanol 180 min after a single dose of 1.5 g/kg, ip were significantly higher in adult male (74 days old, N=5) than in young male rats (34 days old, N = 5): 92.4 ñ 8.4 vs 6.8 + 3.4 mg/lOO ml, means ñ SD, respectively; 2) when male rats were given a low protein diet for 48 h, blood ethanol levels after a single dose were significantly increased in young males (38.6 ñ 14.6 mg/l00 ml) but no effect after a single dose was found in the same animals at an older age (93.2 ñ 5.0 mg/l00 ml); 3) blood levels in female rats were higher than in young males both in the virgin and pregnant states, but during lactation a significant drop in blood levels of ethanol was observed. Blood levels of ethanol (mg/l00 ml) 180 min after a single dose of 1.5 g/kg, ip, in females, were: virgin (N=6): 44.9 ñ 16. 1, pregnant (N = 5): 40.0 ñ 10.4, lactant (N = 5): 8.8 5.8. This difference between virgin and pregnant and lactant rats was not related to changes in ADH activity which did not differ between groups. The present study indicates that in male rats the effect of a short-term protein deprivation on ethanol elimination is dependent on the age of the animal. In females, reproductive state is an important factor in determining ethanol elimination.


Assuntos
Animais , Masculino , Ratos , Feminino , Gravidez , Etanol/farmacocinética , Estado Nutricional/efeitos dos fármacos , Reprodução , Fatores Etários , Álcool Desidrogenase , Análise de Variância , Etanol/administração & dosagem , Lactação , Privação de Alimentos/fisiologia , Deficiência de Proteína , Ratos Wistar
20.
Rio de Janeiro; s.n; 1994. xvi,82 p. ilus.
Tese em Português | LILACS, Coleciona SUS, Inca | ID: biblio-927379

RESUMO

Neste trabalho, o mecanismo cinético de ação da álcool desidrogenase de Thermoanaerobium brockii (TBADH) atuando sobre o sistema isopropanol/acetona foi estudado, visando tanto a elucidação do mecanismo cinético da TBADH quanto explicar o sistema acoplado de reciclagem da coenzima utilizando altas concentrações de isopropanol, 30 (por cento v/v), como co-solvente e co-substrato no meio reacional e com somente uma enzima atuando nas duas reações. Para tanto, realizamos estudos de velocidade inicial de produtos, estudos de inibição por produto e estudos de inibição por formação de complexo "dead-end", nos quais pirazol foi utilizado como inibidor. Os estudos de velocidade inicial na ausência de produtos, forneceram gráficos de Lineweaver-Burk tanto com efeito de inclinação, indicando que o mecanismo cinético era do tipo sequencial. A análise do significado cinético do complexo ternário central, E-coenzima-substrato, sugeriu que o mecanismo cinético era mais provavelmente, do tipo Theorell_Chance Bi-Bi. Nos estudos de inibição por produto objetivemos, gráficos de duplos recíprocos que apresentaram quatro perfis de inibição do tipo competitiva linear (entre NADP e NADPH e entre isopropanol e acetona) e quatro perfis de inibição do tipo mista linear (entre NADP e acetona e entre NADPH e isopropanol), desta maneira os mecanismos cinéticos dos tipos sequencial ordenado Bi-Bi, em estado estacionário, e sequencial ao acaso Bi-Bi, em estado estacionário foram totalmente descartado. Através do estudo de inibição por formação de complexo "dead-end, o mecanismo cinético do tipo sequencial ao acso Bi-Bi, em rápido equilíbrio, foi descartado, ficando caracterizado que no mecanismo cinético proposto a coenzima atua como o primeiro substrato a se ligar à forma livre de enzima. Ambos os parâmetros cinéticos e termodinâmicos da reação foram estimados, pelos ajustes das respectivas equações de velocidade aos dados experimentais obtidos, utilizando-se um programa de computador de regressão não linear e um prorama de computador baseado no método de Hooke-Jeeves, método de procura direta comaceleração em distância, ambos desenvolvidos em nosso laboratório. O ajuste da equação de velocidade inicial para a inibição por formação de complexo "dead-end", forneceu uma estimativa da constante de dissociação...


The kinetic mechanism of the redox reaction isopropanoVacetone catalyzed by Thermoanaerobium broe/ai alcohol dehydrogenase (TBADH) was studied aiming both elucidation of the kinetic mechanism and gaining insight into the coupled-substrate approach that has been extensively used for NADPH regeneration, by using high concentrations of isopropanol, 30% (v/v), as a co-solvent and co-substrate in preparative-scale reductions of carbonyl compounds. For this purpose, initial velocity studies in the absence of products, product inhibition studies and dead-end inhibition studies, using pyrazole , were performed. Initial velocity studies in the absence of products in the forward (isopropanol oxidation) and reverse (acetone reduction) reactions showed that all the double reciprocal plots were of the intersecting type, indicating that the kinetic mechanism of TBADH is of the sequential type, involving ternary or central complexes not necessarily significant kinetically. Kinetic evaluation of the significance of the central complexes, E-coenzymes-substrates, suggested that the mechanism is most probably of the Theorell-Chance Bi-Bi type The patterns obtained in product inhibition studies consisted in four linear competitive inhibitions (between NADP and NADPH, as well as, between isopropanol and acetone) and four linear mixed type inhibitions (between NADP and acetone, as well as, between NADPH and isopropanol). With these studies both the steady-state sequential ordered Bi-Bi mechanism and the steady-state random sequential Hi-Hi mechanism could be ruled out. Dead-end inhibition studies, using pyrazole as inhibitor, showed that NADP is the first substrate to bind to the enzyme followed by the binding of isopropanol, then the rapid equilibrium random sequential Bi-Bi mechanism was also ruled out. Both the kinetic and thermodynamic parameters of the reaction were estimated with a non-linear regression analysis computer program and a computer program based on the Hooke-Jeeves direct search method, both developed in our laboratory. The fitting of the dead-end inhibition equation, with formation of a TBADHNADP-pyrazole complex to the experimental data obtained in the presence of the deadend inhibitor gave estimates of the pyrazole dissociation constant of the E-NADPpyrazole complex, as well as, of the NADP dissociation constant of the same complex. The values obtained for these dissociation constants, when compared to those obtained with horse liver alcohol dehydrogenase, enable us to suggest a model for the structure of the ternary complex TBADH-NADP-pyrazole, in which the interaction of pyrazole occurs only by a coordinate bond formed between one of the heterocyclic nitrogen atoms of the inhibitor with a zinc atom, probably present at the active site of the enzyme. The Theorell-Chance Bi-Bi kinetic mechanism, proposed in this study, satisfactorily explains the recycling process of the coenzyme NADPH, using high concentrations of isopropanol 30 % (v/v), as a co-solvent and co-substrate in preparative-scale enantioselective reactions reduction. Since the coenzyme is the first substrate to bind the free form of the enzyme in a sequential and compulsory order, the interaction of isopropanol with the free form of the enzyme is not possible. Thus preventing TBADH to be saturated with isopropanol. In this way, free TBADH will always be available to catalyze the reduction of the oxidized substrate and the NADP formed in this reaction, continuously reduced to NADPH by isopropanol oxidation concomitantly catalyzed by the same enzyme.


Assuntos
Álcool Desidrogenase , Cinética
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