RESUMO
The antioxidant and radioprotector properties of gamma-linolenic acid isolated from the seeds of Borago officialis were studied on rats gamma-irradiated to a dose of 1 Gy. The irradiation caused an increase in the content of malonaldehyde in microsomal liver fraction and disturbed the metabolism of xenobiotics. The administration of gamma-linolenic acid in the form of a commercial drug Neoglandin (daily dose, 150 mg/kg, p.o.; over 1, 3, or 7 days after irradiation reduced the level of lipid peroxidation (for all treatment schedules), normalized the activity of NADPH-oxidase, NADH-oxidase, and NADPH-reductase, and increased the content of cytochromes P-450 and b5 as compared to bothirradiated and control animals.
Assuntos
Antioxidantes/farmacologia , Microssomos Hepáticos/metabolismo , Fitoterapia , Lesões por Radiação/metabolismo , Protetores contra Radiação/farmacologia , Ácido gama-Linolênico/farmacologia , Animais , Borago , Sistema Enzimático do Citocromo P-450/metabolismo , Citocromos b5/metabolismo , Transporte de Elétrons , Hidroxilação , Peroxidação de Lipídeos , Masculino , Microssomos Hepáticos/enzimologia , Óleos de Plantas/uso terapêutico , Lesões por Radiação/enzimologia , RatosRESUMO
Chronic ethanol administration resulted in a decrease of rat liver linoleoyl-CoA desaturase activity and an activation of MEOS. This was accompanied by an increase in the activity of the NADPH-dependent system and the oxidation rate of NADH-oxidase, which suggests transfer of electrons from NADH to cytochrome P-450. The decreased linoleoyl-CoA desaturase activity may be due to insufficient supply of electrons, because of possible diversion to MEOS.
Assuntos
Etanol/metabolismo , Ácidos Graxos Dessaturases/metabolismo , Fígado/enzimologia , Microssomos Hepáticos/fisiologia , Animais , Redutases do Citocromo/metabolismo , Citocromo-B(5) Redutase , Linoleoil-CoA Desaturase , Masculino , Microssomos Hepáticos/enzimologia , Complexos Multienzimáticos/metabolismo , NADH NADPH Oxirredutases/metabolismo , Oxirredução , Ratos , Ratos EndogâmicosRESUMO
Long-term ethanol load resulted in a decrease of the rat liver linoleyl desaturase activity and the activation of MEOS accompanied by an increase in the activity of NADPH-dependent chain and the initial steps of NADH-dependent chain of microsomal electron transport, indicating electron transfer from NADH to cytochrome P-450. It is suggested that, when the main potential of NADH- and NADPH-dependent chains is transferred to microsomal ethanol oxidation, insufficient electron supply for linoleyl-CoA desaturase decreases the activity of this process.
Assuntos
Alcoolismo/enzimologia , Etanol/metabolismo , Ácidos Graxos Dessaturases/metabolismo , Microssomos Hepáticos/enzimologia , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , Grupo dos Citocromos b/metabolismo , Citocromos b5 , Transporte de Elétrons , Linoleoil-CoA Desaturase , Masculino , NADH NADPH Oxirredutases/metabolismo , Oxirredução , RatosRESUMO
After subcutaneous administration into male rats of 4-phosphopantothenic acid and pantethine during 10 days at a dose equivalent to 30 mg/kg of calcium pantothenate total content of CoA was increased in liver tissue. Both these preparations activated the liver endoplasmic reticulum monooxygenase system mainly at the step of substrate hydroxylation. The phenomenon observed appears to occur due to activation of cytochrome P-450 biosynthesis and/or to alterations in phospholipid composition of microsomal membranes.
Assuntos
Coenzima A/biossíntese , Sistema Enzimático do Citocromo P-450/metabolismo , Fígado/enzimologia , Animais , Peróxidos Lipídicos/metabolismo , Masculino , Lipídeos de Membrana/metabolismo , Microssomos Hepáticos/enzimologia , Panteteína/análogos & derivados , Panteteína/farmacologia , Ácido Pantotênico/análogos & derivados , Ácido Pantotênico/farmacologia , RatosRESUMO
Stimulation of lipid peroxidation in the liver microsomal fraction and alteration in the xenobiotic metabolism were found within twelve hrs after a single vitamin D2 administration (960,000 MU/kg) into male rats. The effects observed appear to occur due to the vitamin D2 prooxidative properties.
Assuntos
Ergocalciferóis/farmacologia , Peróxidos Lipídicos/metabolismo , Fígado/enzimologia , Oxigenases de Função Mista/metabolismo , Animais , Biotransformação , Sistema Enzimático do Citocromo P-450/metabolismo , Fígado/metabolismo , Masculino , Microssomos Hepáticos/enzimologia , Microssomos Hepáticos/metabolismo , Oxirredução , RatosAssuntos
Peróxidos Lipídicos/biossíntese , Microssomos Hepáticos/metabolismo , Deficiência de Tiamina/metabolismo , Aminopirina/metabolismo , Compostos de Anilina/metabolismo , Animais , Ácido Ascórbico/farmacologia , Sistema Enzimático do Citocromo P-450/análise , Etilmorfina/metabolismo , Hidroxilação , Masculino , NADP/farmacologia , Ratos , Fatores de Tempo , Transcetolase/metabolismoRESUMO
Experiments on mongrel albino male rats have shown that a single subcutaneous administration of thiamine in a dose of 200 mg/kg raises in the liver microsomes the level of cytochromes P-450 and B5 and increases the activity of aniline-n-hydroxylase ethylmorphine and aminopyrine-N-demethylase. Administration of the vitamin in a dose of 30 mg/kg for 64 days forces down the cytochrome P-450 and the aniline-n-hydroxylase and ethylmorphine-N-demethylase levels. In vitro tests the P-450 and B5 cytocrome levels and the activity of ethylmorphine-N-demethylase in the liver microsomes start to decrease at the thiamine concentration of 1 mM and of aminopyrine-N-demethylase of 4 mM.