RESUMO
Plasma prednisolone levels have been measured hourly in children receiving a single dose of oral prednisone. Peak prednisolone levels occurred one to two hours after ingestion; half-life studies gave a mean value of 132 minutes in most children. Some children had marked variability in absorption and metabolism of prednisone. Somatomedin activity and cell-mediated immunity were inhibited by plasma prednisolone values which were achieved by single doses of prednisone of 0.5 mg/kg or higher. Monitoring prednisolone levels may be of value in identifying those children who accumulate excessively high levels on moderate dosage regimens.
Assuntos
Prednisolona/sangue , Administração Oral , Adolescente , Hiperfunção Adrenocortical/tratamento farmacológico , Asma/tratamento farmacológico , Disponibilidade Biológica , Criança , Pré-Escolar , Doença de Crohn/tratamento farmacológico , Dermatomiosite/tratamento farmacológico , Feminino , Meia-Vida , Humanos , Imunidade Celular/efeitos dos fármacos , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Masculino , Síndrome Nefrótica/tratamento farmacológico , Prednisolona/administração & dosagem , Prednisolona/metabolismo , Prednisolona/uso terapêutico , Somatomedinas/sangueRESUMO
The presence of a 5beta-reductase acting to convert progesterone to 5beta-pregnane-3,20-dione is described in the soluble 105,000 x g fraction of a preparation of dog cerebral cortex. The function of this enzymatic activity is obscure but may be important in regulation of sensorium. 5beta-pregnane compounds are potent depressors of the central nervous system.
Assuntos
Córtex Cerebral/enzimologia , Hidroxiesteroide Desidrogenases/metabolismo , Pregnanodionas/metabolismo , Progesterona Redutase/metabolismo , Progesterona/metabolismo , Animais , Cristalização , Cães , TrítioRESUMO
The incorporation of radioactive acetate into the digitonin precipitable fraction (cholesterol) was measured in monolayers of primary cultures of skin fibroblasts. Mean incorporation was increased approximately 20-fold in 4 subjects homozygous for familial hypercholesterolemia (FH) and 4-fold in 6 heterozygotes derived from the immediate family of homozygotes. Incorporation was normal in 4 subjects with Type IV and V hyperlipoproteinemia. In cells that had been preincubated in lipid free medium, incorporation by cells from homozygotes was equal to controls, denoting a derangement in the feedback inhibition of cholesterol synthesis by medium lipids in paralleled the values obtained for sterol synthesis. The assay described could be useful in making an "etiologic" diagnosis of familial hypercholesterolemia and could possible identify variants of monogenic hyperbetalipoproteinemia.
