RESUMO
The present method involves conversion of the aldehyde produced, as a result of serotonin deamination by monoamine oxidase, to its 2:4 dinitrophenyl hydrazone derivative which gives a stable, bright yellow colour in alkaline solution and can be measured colorimetrically. The derivative is however unstable in the acidic medium and has to be extracted into an organic solvent immediately. The details of the method and its standardization are discussed.
Assuntos
Animais , Colorimetria , Desaminação , Cobaias , Fígado/enzimologia , Monoaminoxidase/metabolismo , Ratos , Serotonina/metabolismoRESUMO
Monoamine axodation has been studied in different organs of adult rats. Activity of monoamine dehydrogenase (MADH) has been measured both aerobically and anaerobically. Brain is the organ where maximum activity of MADH has been observed while in ovary the minimal enzyme activity has been noticed. In the absence of air, the activity proceeded at faster rate whereas MAO activity cannot take place in absence of oxygen. Oxygen can not be replaced by other electron acceptors like NTC. However, in some organs like pancreas, the formazan production was almost negligible. Aerobically moderate MADH activity was observed in case of ileum and testis. On the other hand, spleen, brain, testis and lung homogenates showed moderate amount of tetrazolium salts reduction in absence of air. This indicates the differential nature of the MADH activities in aerobic and anaerobic condition. High activity of monoamine oxidase (MAO) has been observed in liver. Brain and pancreas were also found good organs for MAO activity, but liver homogenate failed to reduce tetrazolium salt. Only dialysed liver homogenate in the presence of tryptamine, demonstrated moderate activity of MADH. Relative activity of both the enzymes has been studied. The organwise distribution pattern of MAO and MADH appeared quite different.
Assuntos
Aerobiose , Anaerobiose , Animais , Íleo/enzimologia , Fígado/enzimologia , Monoaminoxidase/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Coelhos , Ratos , Distribuição TecidualRESUMO
MAO and MADH activities in different sub-cellular fractions of rat brain have been studied. The sub-cellular distribution pattern of MAO and MADH was found to be same, mostly concentrated in the mitochondrial fraction, although activities were also present in microsome and nucleus.
Assuntos
Animais , Encéfalo/enzimologia , Monoaminoxidase/metabolismo , Ratos , Frações Subcelulares/enzimologia , Sais de Tetrazólio , Triptaminas , TiraminaRESUMO
Amphetamine, ephedrine, mescaline and chlorpromazine act as substrate for dehydrogenase system of rat brain homogenate. This system appears quite different from the usual deaminating process of these compounds, which required NADP and oxygen. The present system proceeds more rapidly in anaerobic condition.