RESUMEN
In experiments on an isolated liver of animals ion-exchange chromatography of the concentration of free amino acids in the perfusate has shown that amino acids with branched chains are metabolized by the liver tissue to a less measure than other amino acids. Under high protein diet the liver capacity for metabolizing most amino acids, except valin, leucin and isoleucin is increased. The data obtained are discussed from the standpoint of transformation of amino acids with branched chains.
Asunto(s)
Aminoácidos de Cadena Ramificada/metabolismo , Hígado/metabolismo , Absorción , Adaptación Fisiológica/efectos de los fármacos , Animales , Proteínas en la Dieta/administración & dosificación , Radicales Libres , Técnicas In Vitro , Ratas , Factores de TiempoRESUMEN
The method of long-time protein electrophoresis in a gradient polyacrylamide gel with a linear change of acrylamide concentration along the gel column was used to determine the molecular mass of protein molecules and their geometric sizes. In our investigation great attention was paid to the determination of the molecular form by the peak width in densitograms of protein fractions. Besides experimental data a possible physical interpretation of the essense of empiric equation is suggested.
Asunto(s)
Electroforesis en Gel de Poliacrilamida/métodos , Proteínas , Peso Molecular , Proteínas/análisis , Factores de TiempoRESUMEN
A mathematical intepretation is given for the published data on the kinetics of proliferation of the hepatocytes during ontogenesis and liver regeneration. The equations were obtained which described the age dependence of the mitotic cycle duration, the time of the cell number was found prior to the sexual maturation of the animals; the minimal and regeneration; a "break" of the curve describing the change of the time of duplication of the cell number was found prior to the sexual maturation of the animals; the minimal duration of the mitotic cycle and the time of duplication of the cell number during ontogenesis and liver regeneration was estimated; the age of animals was established at which the mitotic cycle of hepatocytes had the same duration as at the definite stage of liver regeneration.
Asunto(s)
Envejecimiento , Regeneración Hepática , Hígado/citología , Mitosis , Animales , Ciclo Celular , División Celular , Cinética , Matemática , Modelos Biológicos , Ratas , Factores de TiempoRESUMEN
The distribution of carbonic anhydrase, K+-ATPase and K+-phosphatase in the subcellular fractions of gastric mucosa was studied. It was found that 90% of carbonic anhydrase are localized in the hyaloplasm, whereas K+-ATPase and K+-phosphatase are predominantly localized in the microsomal fraction. Subfractionation of the microsomal fraction in a sucrose density gradient showed that the membrane-bound carbonic anhydrase (5% of total content) and K+-ATPase are bound to various cell organelles. It is concluded that carbonic anhydrase functions as an intracellular pH-stat and is not directly involved in proton generation by the cell.
Asunto(s)
Adenosina Trifosfatasas/metabolismo , Anhidrasas Carbónicas/análisis , Mucosa Gástrica/enzimología , Monoéster Fosfórico Hidrolasas/metabolismo , Animales , Fraccionamiento Celular , Masculino , Potasio/metabolismo , Conejos , Fracciones Subcelulares/enzimologíaRESUMEN
A nomograph is suggested using which one can determine from the molecular weight and one of the dimensions of the molecule the remaining dimension and the axial ratio for the ellipsoid of rotation with the volume equivalent to the volume of the protein molecule. The nomograph permits to determine molecular weight from the molecular size of the dry protein and of the protein dissolved in water. From the molecular size of the dry protein corresponding dimensions for the protein molecule in an aqueous solution can be obtained. At last the nomograph can help to evaluate the correctness of the literature data and experimental data on the molecular sizes of proteins and on their molecular weights.
Asunto(s)
Proteínas , Fenómenos Químicos , Química Física , Peso Molecular , Soluciones , AguaRESUMEN
Following determination by the method of ion-exchange chromatography of free amino acids in the blood drawn from the portal and liver veins and the abdominal aorta 30 minutes after introduction of a casein suspension to rats it was found that only 50 per cent of amino acids with ramified chain are retained in the liver. Most of the other amino acids, however, become metabolized largely in the liver and it is only their insignificant part that goes into the general circulation. These data may be of use in considering problems related to the peculiarities of metabolism of amino acids with ramified chain.
Asunto(s)
Aminoácidos/metabolismo , Hígado/metabolismo , Aminoácidos/sangre , Animales , Aorta Abdominal/análisis , Caseínas/administración & dosificación , Radicales Libres , Venas Hepáticas/análisis , Técnicas In Vitro , Masculino , Vena Porta/análisis , RatasRESUMEN
Estimation of molecular weights of the glucose-6-phosphate dehydrogenase (G6PD) multiple forms was carried out by the method of extended electrophoresis (within 24 hrs) in polyacrylamide gel with linear gradient of concentration (from 3.5% to 30%). Proceeding from the variations in molecular weight, the multiple forms of G6PD, found in liver tissue and adrenal glands, might be apparently classified as two types, designated as alpha-G6PD and beta-G6PD. The possible reasons are discussed for the existence of two types of G6PD in the one organ.
Asunto(s)
Glándulas Suprarrenales/enzimología , Glucosafosfato Deshidrogenasa , Isoenzimas , Hígado/enzimología , Animales , Peso Molecular , RatasRESUMEN
Distribution of mitoses and dead hepatocytes in the hepatic balk was investigated. A relative rate of the hepatocyte movement along the hepatic balk was calculated on the basis of this distribution. The direction and the rate of the hepatocyte movement along the hepatic balk were determined by measurement of the shift of the labelled cell peak a month after six thymidine-H3 injections.