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Volume 10, Issue 1
Displaying 1-7 of 7 articles from this issue
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Takeshi HOSHI1985 Volume 10 Issue 1 Pages 2-12
Published: January 01, 1985
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSTranscellular transport of physiologically important substances across cellular membranes (epithelia) is achieved through two distinct membrane processes in series, the apical and basolateral membrane steps, and the paracellular pathways. In cases of active transport, only one of the membrane processes is uphill. Uphill processes can be divided into three categories according to the mode of. energy utilization; primary, secondary and tertiary. The direction of transcellular transport (absorption or secretion) is determined by the location and direction of the uphill membrane transport.
Transcellular transport of nutrients by epithelia is coupled with Na+. Na-coupled cotransport mechanisms (secondary active processes) in the apical membranes take up the respective substrates in a uphill manner causing intracellular accumulation of the substrates, which exit across the basolateral membranes along their gradients formed. Molecular properties and carrier mechanisms of the cotransport has partly been elucidated. For Na+or Ca++, a primary active process at the basolateral membrane is responsible for transcellular active transport, whereas active transport of Cl-, phosphate, SO4- is secondary active process coupled with Na+. In some cell types, 2Cl-/Na+/K+ cotransport is responsible for active Cl- transport. Characteristics of these different types of ion transport is to be outlined.View full abstractDownload PDF (1706K) -
Takeo Shimidzu, Hikaru Koide, Yoshimasa Orita, Hiroshi Tanzawa, Kiyota ...1985 Volume 10 Issue 1 Pages 13-23
Published: January 01, 1985
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSDownload PDF (1920K) -
Fumio KUKITA1985 Volume 10 Issue 1 Pages 25-35
Published: January 01, 1985
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe effects of osmotic pressure on the nerve excitation in the squid giant axon were described. The osmotic pressure affected the nerve excitation in two different ways : (1) in the absence of its difference across the membrane, an increase in osmorality and an increased microscopic viscosity of solutions slowed down the kinetics of nerve excitation, and (2) in the presence of its difference, a net water flow occurred across the membrane, and this water movement affected ionic channels in a direct and an indirect manner. The latter effects on K-channel revealed qualitative differences from those on Na-channel. Further anylysis of these osmolarity effects on ionic channels may prove valuable in clarifying the molecular mechanism of nerve excitation.View full abstractDownload PDF (1474K) -
Yoshio ODA1985 Volume 10 Issue 1 Pages 36-44
Published: January 01, 1985
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe functions required for membranes in separation processes were elucidated from the industrial point of view and then the application of the membranes composed of various functional materials was briefly summerized. For industrial uses the stability of the membranes under actually used conditions is very important as well. Compared with hydrocarbon type membranes, fluorocarbon type membranes developed recently are so stable that they meet the severe requirement for industrial uses. The synthesis, properties and applications of perfluorinated cationexchange membranes were reveiwed. In recent application, this type membrane has been widely used in the brine electrolysis where it is exposed to chlorine and strong caustic at high temperatures. A perfluorinated anion-exchange membrane whose development was more recently announced was touched upon in a few words.View full abstractDownload PDF (1223K) -
Mamoru NAKANISHI1985 Volume 10 Issue 1 Pages 45-52
Published: January 01, 1985
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe process of recognition among cells of immune system provides one of the most interesting molecular problems in membrane biology today. To solve such problems, we have investigated the immunological reactions on the membrane from various aspects. First, we have found that the binding reaction of antibodies with fluorescent lipid haptens in model membranes is dependent on the membrane fluidity, whereas the rotational motion itself is almost independent. We have also found that the binding of macrophages to lipid monolayers containing lipid haptens is dependent on the membrane fluidity, while the spreading is independent. All the results are discussed in terms of the recognition and triggering of macrophages on the membrane surfaces. Next, we have developed procedures for reconstituting transmembrane proteins into supported planar lipid monolayers. These monolayer membranes are shown to be useful for studying receptor-specific regulation of cell-mediated immune response. Last, w have studied the initial recognition steps of target tumor cells by monoclonal antibody against mouse MHC antigen. Ca2+ influx, redistribution of membrane-bound Ca2+ and membrane fluidity after the binding of the antibody to the target tumor cells have been well characterized by stopped-flow fluorometry.View full abstractDownload PDF (1281K) -
New concepts of calcium mobilizationYoshinori NOZAWA1985 Volume 10 Issue 1 Pages 53-64
Published: January 01, 1985
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSIt is generally accepted that the rapid turnover of membrane phospholipids may play a pivotal role in calcium mobilization in the stimulus-response coupling. The breakdown of inositol phospholipids is considered to be a cause but not a consequence of calcium mobilization. Substantial evidence indicates that inositol triphosphate (IP3) derived from triphosphoinositide by action of phosphodiesterase serves as a calcium releaser from intracellular organelles, probably endoplasmic reticulum. However, the precise mechanism of the molecular mechanism at the molecular level of the transient increase of calcium ion induced by cellular activation has not yet been clarified. In this article, the recent concepts regarding calcium signal in the stimulated cells are reviewed.View full abstractDownload PDF (1544K) -
I. Power balance equation and elemental circuit modelY. IMAI, H. YOSHIDA, M. MURAKAMI1985 Volume 10 Issue 1 Pages 65-73
Published: January 01, 1985
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThough the network thermodynamics was introduced by Oster et al for modelling the bioenergy system, only few concrete utilities were reported. One of the reasons is in the insufficient representation on the power coupling mechanism in their papers. In this paper, we study the basic elements for the circuit model of power system by introducing the new “power balance equation”. The basic elements are classifed three generalized elements which represent respectively the free energy change, the power dissipation on each power species and the power coupling between two power species in the system. The capacitors and the resistors for each power species and the transformer type transducers for the coupling -representation are devised as principal elements in the circuit model of membrane transport system. We show the coupled two-powers system can be synthesized as an elemental circuit model. The membrane transport system consisting of the water and non-electrolyte flows is also represented by the elemental circuit model.View full abstractDownload PDF (1116K)
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