RESUMO
There are few reports of the effects of glutathione-depleting agents administered for periods longer than 24 hr on the turnover of glutathione (GSH) in mammalian tissues. Studies of such effects are important in relation to the protection of tissues from damage from, for example, reactive metabolites derived from xenobiotics. In the investigation described here, 1,2-dibromoethane dibromide)-a widely used insecticide, nematocide, fungicide and petrol additive, which is hepato- and nephrotoxic-was administered to rats and the effects on non-protein thiol contents and GSH-related enzyme activities were determined in liver and kidney. The classical GSH-depleter diethylmaleate was used in parallel studies for comparative purposes.
Assuntos
Dibrometo de Etileno/farmacologia , Glutationa/metabolismo , Hidrocarbonetos Bromados/farmacologia , Rim/metabolismo , Fígado/metabolismo , Animais , Feminino , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Maleatos/farmacologia , Ratos , Ratos Endogâmicos , Fatores Sexuais , Compostos de Sulfidrila/análiseAssuntos
Avaliação da Deficiência , Pensões , Feminino , Humanos , Relações Médico-Paciente , Reino UnidoRESUMO
In a group of 19 subjects suffering from erythropoietic protoporphyria the administration of beta-carotene appeared to produce improvement based on a subjective assessment of alterations in exposure times required to produce the symptoms and signs of the condition. This clinical improvement however failed to show a direct correlation with the prophyrin levels in blood and faeces, or with the estimation by phototesting of the minimal response dose within the action spectrum of 400-600 nm.
Assuntos
Carotenoides/uso terapêutico , Porfirias/tratamento farmacológico , Adolescente , Adulto , Idoso , Carotenoides/sangue , Criança , Pré-Escolar , Relação Dose-Resposta à Radiação , Eritrócitos/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Porfirias/metabolismo , Porfirinas/metabolismo , Protoporfirinas/sangue , Luz Solar , Vitamina A/sangueRESUMO
The paraquat content of urine can be directly determined by high-speed liquid chromatography using ultraviolet spectrophotometric detection. The method separates paraquat (and diquat) from the ultraviolet-absorbing components of urine and no extraction or pre-treatment of the sample is required prior to analysis. Concentrations down to 100 mug/1 of paraquat in urine were determined. Quantitative results are in good agreement with those obtained by a colorimetric method. Diquat does not interfere with the analysis of paraquat, and it would also be possible to analyse diquat in paraquat-containing urine.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Paraquat/urina , Absorção , Diquat/urina , Humanos , Microquímica , Solventes , Espectrofotometria UltravioletaRESUMO
Seven patients undergoing treatment for cutaneous hepatic porphyria had serial measurements of their plasma uroporphyrin. In each case there was a progressive fall during treatment but even in remission the levels did not return to normal. There was a significant correlation between urinary and plasma uroporphyrin concentrations.
Assuntos
Porfirias/sangue , Porfirinas/sangue , Uroporfirinas/sangue , Adulto , Idoso , Consumo de Bebidas Alcoólicas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Plasmaferese , Porfirias/terapia , Uroporfirinas/urinaAssuntos
Microssomos Hepáticos/metabolismo , Tolbutamida/sangue , Radioisótopos de Carbono , Cromatografia em Camada Fina , Sistema Enzimático do Citocromo P-450/metabolismo , Redutases do Citocromo/metabolismo , Grupo dos Citocromos c , Jejum , Meia-Vida , Humanos , Cinética , Fígado/enzimologia , Análise de Regressão , Fatores de Tempo , Tolbutamida/metabolismoAssuntos
Microssomos Hepáticos/metabolismo , Tolbutamida/metabolismo , Ureia/metabolismo , Animais , Autopsia , Biópsia , Isótopos de Carbono , Feminino , Humanos , Hidroxilação , Cinética , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Técnicas de Cultura de Órgãos , Pentobarbital/farmacologia , Ratos , Fatores de TempoRESUMO
1. Lactating female rats were treated with phenobarbitone or chlorpromazine. 2. Hepatic microsomal fractions from the suckling offspring were studied to see if changes had occurred in the rates of drug metabolism. 3. Treatment with phenobarbitone significantly increased the cytochrome P-450 concentration, the activity of NADPH-cytochrome c reductase (EC 1.6.2.3) and the rates of metabolism of aniline, ethylmorphine and [2-(14)C]pentobarbitone. 4. Treatment with chlorpromazine produced only small increases in the cytochrome P-450 concentration and the rate of hydroxylation of aniline.
Assuntos
Animais Recém-Nascidos/metabolismo , Clorpromazina/farmacologia , Lactação , Fígado/metabolismo , Fenobarbital/farmacologia , Compostos de Anilina/metabolismo , Animais , Isótopos de Carbono , Citocromos/análise , Feminino , Formaldeído/biossíntese , Hidroxilação , Fígado/efeitos dos fármacos , Leite , Morfinanos/metabolismo , Oxirredutases/metabolismo , Pentobarbital/metabolismo , Gravidez , RatosAssuntos
Compostos de Anilina/metabolismo , Codeína/metabolismo , Hexobarbital/metabolismo , Microssomos Hepáticos/metabolismo , Idoso , Citocromos/análise , Indução Enzimática , Feminino , Humanos , Masculino , Microssomos Hepáticos/enzimologia , Pessoa de Meia-Idade , NADP , Oxirredução , Oxirredutases/análise , Espectrofotometria , SulfitosRESUMO
1. Houseflies, blowflies and New Zealand grass grubs were dosed with 1-naphthol, 2-naphthol or p-nitrophenol. 2. The corresponding monoaryl phosphates were identified in extracts of insects or excreta along with the beta-glucosides and ethereal sulphates of the phenols. 3. No diaryl phosphates or glucosiduronates were detected but an unidentified metabolite of [(14)C]1-naphthol was present in extracts of flies dosed with [(14)C]1-naphthol.
Assuntos
Dípteros/metabolismo , Insetos/metabolismo , Nitrofenóis/metabolismo , Fenóis/metabolismo , Fosfatos/metabolismo , Cromatografia em Papel , Glicosídeos/análise , IontoforeseRESUMO
1. Glutathione-S-aryltransferase activity from grass grubs (Costelytra zealandica) was inhibited by phthaleins, sulphonphthaleins and some dicarboxylic acids. 2. These compounds had no detectable action on the enzyme from sheep liver. 3. In insect enzyme the inhibition was competitive with respect to glutathione and non-competitive with respect to the aromatic substrate. 4. Michaelis constants and inhibitor constants were measured for sheep-liver or grass-grub enzyme between pH5 and pH10 and evidence was obtained for the presence of two groups with pK9.2 in the glutathione-binding site of the insect enzyme. 5. Only one such group was detected in the sheep-liver enzyme.
