Relation between the glycogen content of the liver and liver weight,and its meaning for enzymology

Zusammenfassung Schwankungen des Glykogengehalts verursachen sehr schnelle Veränderungen des Lebergewichtes und daher auch solche des prozentualne Proteingehalts der Leber. Enzymaktivität sollte deshalb pro Körpergewicht und nicht pro Lebergewicht ausgedrückt werden, wie dies oft geschieht.

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Acknowledgments. The authors wish to express their gratitude ProfessorA. de Minjer for his support, to ProfessorL. W. J. Holleman, ProfessorJ. W. Koten and ProfessorH. Schimassek for helpful suggestions and to Mrs.L. C. Freelink-vander Velden for technical assistance.     

Autophagy and lysosomal proteolysis in the liver

Autophagy is defined as any process whereby cellular macromolecules destined for degradation gain access to the lysosomes. A review is presented on the physiological significance, mechanisms and regulation of autophagy in hepatocytes, concentrating on the issue of regulation. The article ends by discussing techniques available for future research.     

Autophagy and lysosomal proteolysis in the liver

Summary Autophagy is defined as any process whereby cellular macromolecules destined for degradation gain access to the lysosomes. A review is presented on the physiological significance, mechanisms and regulation of autophagy in hepatocytes, concentrating on the issue of regulation. The article ends by discussing techniques available for future research.     

Erythrocyte catalase in liver cirrhosis and in experimental liver injury

Résumé Nous avons trouvé que l'activité de la catalase des erythrocytes chez les cirrhotiques et chez les chiens intoxiqués par CCl₄ est considérablement diminuée, tandis que le numéro globulaire et le taux d'hémoglobine ne représentent que des changements très peu signicatifs.     

Pressure acclimation of the eel and liver membrane composition

Homeoviscous adaptation of membrane fluidity is known to exist in fish living at great depths. Is this adaptation also present in fish living near the surface but experimentally acclimated to high pressure? The composition of mitochondria-rich fractions extracted from the livers of eels acclimated for 15 days at 101 ATA was determined. The results show that pressure induced a significant increase (+100%) of total phospholipids (PL) and cholesterol without a change in their ratio. The increase of PL content was accompanied by a decrease in phosphatidylcholine in favour of phosphatidyl ethanolamine which, due to its preference for the H₁₁ form, is able to compensate for the loss in fluidity induced by pressure.     

Prednisolone-binding proteins in the rat liver and gastrocnemius muscle

Summary Quantitatively, liver cytosol preparations were found to contain 2.3 times the number of prednisolone-binding proteins that were present per mg total protein in the rat gastrocnemius muscle. The liver proteins were larger molecules and, in a low ionic environment, were more chemically stable than the muscle proteins.The authors gratefully acknowledge the advice and encouragement of Dr G.A.J. Goodlad.     

Corticosteroids and the radiation effect in regenerating liver of the rat

Résumé La vitesse de régénération du foie chez le rat surrénalectomisé, irradié, est comparée à celle du rat normal radioprotégé, afin d'établir si la sécrétion des corticostéroides est en partie responsable de l'inhibition de la mitose provoquée par la radiation.Dans le présent travail, il est démontré que le rat surrénalectomisé possède une vitesse de mitose quatre fois supérieure à celle du rat normal, et ceci malgré d'importants dégâts causés au foie par la radiation.     

On the radio-sensitivity of rat liver

Résumé Les lobes antérieurs du foie de rats ont été prélevés et exposés aux rayons-X jusqu'à des doses de 91 kR et en employant comme indicateur biochimique de survivance l'incorporation de³H-leucine. Une dose de 45 kR fit diminuer l'incorporation au cours des 3 premiers jours suivant l'exposition; ce type de blessure de radiation nécessite donc plusieurs jours pour se manifester. Ces rêsultats montrent qu'au commencement de l'interphase l'hépatocyte est extrêmement résistant à la mort par radiation.     

Thiamine triphosphate metabolism and its turnover in the rat liver

Summary When rats were injected with a thiamine disulfide derivative, the content of thiamine triphosphate (TTP) in the liver doubled within 3 h after a preceeding rise in thiamine pyrophosphate; it then returned to the basal level within the next 3h, indicating a net increase of TTP in vivo and its rapid turnover.     

Interaction between the soluble and particulate neuraminidases of chick liver

Summary The sum of the neuraminidase activities found in the isolated soluble and particulate fractions of chick liver was considerably higher than that observed in the cytoplasmic extract from which these fractions were obtained. Addition of increasing amounts of particulate neuraminidase to a constant amount of the soluble preparation resulted in a progressive loss of enzyme activity.This investigation was supported in part by U. S. Public Health Service Grant NS09176 from the National Institutes of Health.     

On the biomechanical function of the liver capsule

Summary We have carried out histomechanical studies on the human and bovine liver capsule under tension loading. Results: Nonlinear force-time curve under extension with constant speed, initial upper and lower summit decrease of the dynamic relaxation curve, amplitude diminution phenomenon of the dynamic relaxation in the lower nonlinear part of the extension-time curve, dynamic (cyclic) force recovery.Acknowledgments. We are grateful for helpful suggestions to Dr P. Freyer. The authors are indebted to Mrs C. Beckers and Mr W. Graulich — The experimental study was supported by the DFG (Deutsche Forschungsgemeinschaft).     

The glutathione status of the rat liver

Summary For the determination of cellular total glutathione, a new method is presented based on a fluorometric procedure. The relation between reduced glutathione, mixed glutathione disulfides and disulfide glutathione will be designated the glutathione status.Supported by DFG (Ha 743/3).