RESUMO
The amino acid composition of proteins from liver mitochondrial membranes has been studied in patients with normal liver, with biliary diseases and fatty liver, with obstructive jaundice or liver cirrhosis. A characteristic pattern of the amino acid composition in patients with normal liver has been found. In the mitochondrial membranes of patients with fatty liver tryptophan and lysine were decreased while [aspartic acid plus asparagine] and [glutamic acid plus glutamine] were increased compared to their counterpart in the normal liver. In patients with obstructive jaundice of short duration (less than two months) only a slight decrease in methionine content was found, while in the case of liver cirrhosis amino acid composition was markedly changed.
Assuntos
Aminoácidos/análise , Doenças Biliares/metabolismo , Membranas Intracelulares/química , Hepatopatias/metabolismo , Mitocôndrias Hepáticas/química , Fracionamento Químico , Colestase/metabolismo , Fígado Gorduroso/metabolismo , Humanos , Metabolismo dos Lipídeos , Lipídeos/química , Cirrose Hepática/metabolismo , Mitocôndrias Hepáticas/metabolismoRESUMO
In order to discriminate between conflicting reports in the literature, plasma and cerebrospinal fluid magnesium levels from epileptic children were compared with those of control children. To exclude the possibility of methodological artifacts, two methods for Mg determination were used: atomic absorption spectrophotometry and a colorimetric procedure. By both methods a significantly decreased concentration of Mg in plasma was found in epileptics. A positive correlation of the hypomagnesemia with the severity of epilepsy was found: the more severe the epilepsy, the lower was the plasma Mg. A significant increase of Mg concentration in CSF of epileptics was found. The most likely origin of Mg in CSF in epilepsy is the CNS tissue from which Mg is released. It is suggested that these alterations of Mg concentrations in plasma and CSF originate from a functional impairment of the cell membranes which might occur in epilepsy.
Assuntos
Epilepsia/metabolismo , Magnésio/análise , Adolescente , Criança , Pré-Escolar , Colorimetria/métodos , Feminino , Humanos , Lactente , Recém-Nascido , Magnésio/sangue , Magnésio/líquido cefalorraquidiano , Masculino , Espectrofotometria AtômicaRESUMO
Detailed lipid analyses of human and rat liver microsomes revealed interesting differences. It was found that human liver microsomes contain twice as much lipid as those from the rat. This increased lipid content is not associated with an increase in content of a particular lipid class; human liver microsomes contain higher amounts of each of the lipid classes. Human and rat liver microsomes differ especially in the essential fatty acid composition of total lipids and phospholipids: human liver microsomes contain more linoleic acid and less arachidonic acid than those of the rat. Such a pattern of distribution of fatty acids is similar to that previously reported for human liver mitochondria and has not been reported for other species. Although the previously reported for human liver mitochondria and has not been reported for other species. Although the unsaturation of lipids is lower in human than in rat liver microsomes, spin label studies revealed a higher fluidity in human membranes. It is suggested that this might arise from a lesser immobilization of lipids by proteins in human liver subcellular membranes.
Assuntos
Lipídeos/análise , Microssomos Hepáticos/ultraestrutura , Animais , Fracionamento Celular , Colesterol/análise , Espectroscopia de Ressonância de Spin Eletrônica , Ácidos Graxos não Esterificados/análise , Glucose-6-Fosfatase/análise , Glucuronidase/análise , Glutamato Desidrogenase/análise , Glicerídeos/análise , Humanos , Fígado/enzimologia , Fosfolipídeos/análise , Ratos , Especificidade da Espécie , Frações Subcelulares/ultraestrutura , Triglicerídeos/análiseRESUMO
The fractionation of human liver mitochondria into inner membrane, outer membrane and matrix material is reported. Compared with rat, human liver mitochondria are more fragile. Fractionation can be achieved in only 2 steps, a digitonin treatment for removal of the outer membrane and centrifugation of the inner membrane plus matrix particles through a linear sucrose gradient resulting in purified inner membranes and matrix.