RESUMO
The oxidation of putrescine in vitro by pig kidney diamine oxidase (EC 1.4.3.6) was increased in the presence of 2-oxosuccinamic acid and malonamic acid. It was inhibited by 3-aminopropionamide, oxaloacetate and pyruvate. 2-Oxosuccinamate was derived from asparagine in virus-transformed baby hamster kidney (BHK) cells growing in tissue culture. Asparagine was decarboxylated more efficiently by transformed than by normal BHK cells. In BHK cells transformed by polyoma virus (Py BHK), 2-oxosuccinamate is the most likely immediate precursor of the 14 CO2 arising from [U-14C] asparagine, and there was some evidence for its formation in an asparagine-dependent clone of BHK cells before and after their transformation by hamster sarcoma virus (respectivey Asn- and HSV Asn-). The relationship between 2-oxosuccinamate and pyruvate and the possible roles of these two substances in controlling cellular diamine oxidase activity are discussed (AU)
Assuntos
Amidas , Amina Oxidase (contendo Cobre) , Asparagina , Alanina , Amina Oxidase (contendo Cobre)/metabolismo , Asparagina/metabolismo , Linhagem Celular , Transformação Celular Neoplásica , Efeito Citopatogênico Viral , Descarboxilação , Ativação Enzimática , Rim/enzimologia , Cinética , Malonatos , Polyomavirus , Putrescina/metabolismo , SuccinatosAssuntos
Ratos , 21003 , Masculino , AMP Cíclico/farmacologia , Cálcio/farmacologia , Epinefrina/farmacologia , Glucagon/farmacologia , Gluconeogênese/efeitos dos fármacos , Rim/metabolismo , Butiratos/farmacologia , Relação Dose-Resposta a Droga , Fumaratos/metabolismo , Glutamina/metabolismo , Córtex Renal/efeitos dos fármacos , Córtex Renal/enzimologia , Córtex Renal/metabolismo , Cinética , Lactatos/metabolismo , Malatos/metabolismo , Modelos Biológicos , /metabolismo , Espectrofotometria Ultravioleta , Inanição , Succinatos/metabolismoAssuntos
Cobaias , 21003 , Masculino , Ácidos Graxos não Esterificados/farmacologia , Mitocôndrias Hepáticas/metabolismo , Fosfoenolpiruvato , Acetoacetatos/farmacologia , Trifosfato de Adenosina/farmacologia , Caprilatos/farmacologia , Citratos/metabolismo , Ciclo do Ácido Cítrico , Ácidos Graxos Insaturados/farmacologia , Ácidos Cetoglutáricos/metabolismo , Malatos/metabolismo , Mitocôndrias Hepáticas/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Ácidos Palmíticos/farmacologia , Succinatos/metabolismoAssuntos
Ratos , 21003 , Antraquinonas , Transporte de Elétrons , Oxirredutases/antagonistas & inibidores , Sítios de Ligação , Candida/citologia , Candida/enzimologia , Ácidos Carboxílicos , Bovinos , Química , Ferricianetos/metabolismo , Flavinas , Flavoproteínas , Cinética , L-Lactato Desidrogenase/antagonistas & inibidores , Malato Desidrogenase/antagonistas & inibidores , Membranas/enzimologia , Mitocôndrias/enzimologia , Mitocôndrias Hepáticas/enzimologia , Miocárdio/enzimologia , NAD/metabolismo , Soroalbumina Bovina , Succinatos/metabolismo , SuínosRESUMO
The drug phenyl ethyl biguanide (PEBG) was used in vivo and in vitro to study further the relationship between renal gluconeogenesis and ammonia production in the rat. When PEBG was injected intraperitoneally into the rats, it caused a decrease in urinary ammonia in spite of a greater degree of systemic acidosis. PEBG injections also blocked the increase in glucose and ammonia production by renal cortical slices from rats which had been made acidotic by oral administration of ammonium chloride 2h previously. With increasing concentrations of PEBG in vitro, there was inhibition of gluconeogenesis and ammonia production from glutamine and glutamate as substrates. The two processes were equally inhibited when glutamate was used as substrate but with glutamine, gluconeogenesis was more inhiblted than ammonia production. The inhibition of renal gluconeogenesis by PEBG in vitro was similar when succinate, oxaloacetate, fructose, glutamine and glutamate were used as substrates. The results show that PEBG does not inhibit gluconeogenesis by blocking a specific site in the gluconeogenic pathway. In addition, further proof is provided of the physiological interrelationship of renal ammonia production and gluconeogenesis (Summary)
