Cell Biology of Reef-Building Corals: Ion Transport, Acid/Base Regulation, and Energy Metabolism

2016 ◽  
pp. 193-218 ◽  
Author(s):  
Martin Tresguerres ◽  
Katie L. Barott ◽  
Megan E. Barron ◽  
Dimitri D. Deheyn ◽  
David I. Kline ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Ion Transport ◽  
Cell Biology ◽  
Acid Base

scholarly journals Extracellular Acid-Base Balance and Ion Transport Between Body Fluid Compartments

Physiology ◽  
2017 ◽  
Vol 32 (5) ◽  
pp. 367-379 ◽  
Author(s):  
Julian L. Seifter ◽  
Hsin-Yun Chang
Keyword(s):  
Ion Transport ◽  
Ph Regulation ◽  
Extracellular Fluid ◽  
Transport Processes ◽  
Electrolyte Balance ◽  
Ph Homeostasis ◽  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance ◽  
Fluid Compartments

Clinical assessment of acid-base disorders depends on measurements made in the blood, part of the extracellular compartment. Yet much of the metabolic importance of these disorders concerns intracellular events. Intracellular and interstitial compartment acid-base balance is complex and heterogeneous. This review considers the determinants of the extracellular fluid pH related to the ion transport processes at the interface of cells and the interstitial fluid, and between epithelial cells lining the transcellular contents of the gastrointestinal and urinary tracts that open to the external environment. The generation of acid-base disorders and the associated disruption of electrolyte balance are considered in the context of these membrane transporters. This review suggests a process of internal and external balance for pH regulation, similar to that of potassium. The role of secretory gastrointestinal epithelia and renal epithelia with respect to normal pH homeostasis and clinical disorders are considered. Electroneutrality of electrolytes in the ECF is discussed in the context of reciprocal changes in Cl−or non Cl−anions and [Formula: see text].

Ion Transport and Energy Metabolism in Brain

1981 ◽  
Vol 3 (1) ◽  
pp. 107-123 ◽  
Author(s):  
Wayne Crowe ◽  
Avraham Mayevsky ◽  
Leena Mela
Keyword(s):  
Energy Metabolism ◽  
Ion Transport

Coupling among changes in energy metabolism, acid-base homeostasis, and ion fluxes in ischemia

1992 ◽  
Vol 70 (S1) ◽  
pp. S170-S175 ◽  
Author(s):  
Ken-ichiro Katsura ◽  
Anders Ekholm ◽  
Bo K. Siesjö
Keyword(s):  
Energy Metabolism ◽  
Ion Homeostasis ◽  
Ion Fluxes ◽  
Acid Base ◽  
Cellular Energy ◽  
Initial Event ◽  
Extra Cellular Fluid ◽  
The Relationship ◽  
Energy Failure ◽  
Ion Conductances

This article attempts correlating changes in cellular energy metabolism, acid-base alterations, and ion homeostasis in ischemia and other conditions. It is emphasized that loss of ion homeostasis, with thermodynamically downhill fluxes of K+, Ca2+, Na+, Cl−, and H+, occurs because energy production fails and (or) ion conductances are increased. In ischemia, energy failure is the leading event but, in hypoglycemia, activation of ion conductances is what precipitates energy failure. The initial event is a rise in K+e, at least in part caused by activation of K+ conductances modulated by Ca2+ or ATP/ADP ratio. Secondarily, this leads to release of excitatory amino acids and massive activation of unspecific cation (and anion) conductances. Production of H+ occurs in states characterized by energy failure (ischemia and hypoxia) or by alkalosis (hypocapnia and ammonia accumulation). H+ equilibrates between intra- and extra-cellular fluid via nonionic diffusion of lactic acid, and transmembrane fluxes of H+ or HCO3− via ion channels. Since the relationship between lactate and either pHi or pHe is linear, there are no abrupt pH shifts explaining why hyperglycemia worsens ischemic damage. The reversible insults seem to induce a sustained stimulation of H+ extrusion from cells giving rise to intracellular alkalosis and extracellular acidosis.Key words: energy metabolism, acid-base homeostasis, ion fluxes, ischemia.

Energy metabolism and ion transport studied in single neurons

PROTOPLASMA ◽  
1967 ◽  
Vol 63 (1-3) ◽  
pp. 52-55 ◽  
Author(s):  
Ezio Giacobini
Keyword(s):  
Energy Metabolism ◽  
Ion Transport ◽  
Single Neurons

Correlations between energy metabolism, ion transport, and water content in astrocytes

1992 ◽  
Vol 70 (S1) ◽  
pp. S350-S355 ◽  
Author(s):  
James E. Olson ◽  
Julie A. Evers
Keyword(s):  
Energy Metabolism ◽  
Ion Transport ◽  
Water Content ◽  
Neonatal Rat ◽  
Extracellular Potassium ◽  
Osmotic Swelling ◽  
A Cell ◽  
Phosphate Buffered Saline ◽  
The Brain ◽  
Extracellular Environment

Energy metabolism, ion transport, and water content are interrelated in mechanisms of homeostasis of the brain intracellular and extracellular environment. The simplest model of cell homeostasis, the pump–leak hypothesis, incorporates basic relationships between these variables. Although this model accurately calculates steady-state cell volumes, ion concentrations, and metabolic rates, it fails to predict dynamic changes in these properties during elevated extracellular potassium, metabolic inhibition, and osmotic swelling. We have investigated relationships between ions, energy metabolism, and water content in cerebral astrocytes cultured from the neonatal rat. These cells swell more in hypoosmotic phosphate-buffered saline (PBS) containing NaCl than in hypoosmotic PBS with all NaCl replaced equiosmotically by sucrose. Unidirectional Na+ influx also is greater in cells suspended in hypoosmotic, compared with isoosmotic PBS. These data suggest that astrocytes possess a cell volume dependent mechanism of Na+ accumulation. The influx of Na+ during swelling may be coupled to metabolism via Na–K ATPase and may contribute to the sustained swelling of astrocytes observed in hypoosmotic swelling of the brain in situ.Key words: sodium, hypoosmolality, sodium–potassium adenosine triphosphatase, mathematical modeling.

Ion homeostasis, channels, and transporters: an update on cellular mechanisms

2004 ◽  
Vol 28 (4) ◽  
pp. 143-154 ◽  
Author(s):  
George R. Dubyak
Keyword(s):  
Ion Channels ◽  
Subcellular Localization ◽  
Ion Transport ◽  
Membrane Transport ◽  
Cell Biology ◽  
Functional Characterization ◽  
Transport Proteins ◽  
Transport Protein ◽  
Membrane Transport Proteins ◽  
Functional Analyses

The steady-state maintenance of highly asymmetric concentrations of the major inorganic cations and anions is a major function of both plasma membranes and the membranes of intracellular organelles. Homeostatic regulation of these ionic gradients is critical for most functions. Due to their charge, the movements of ions across biological membranes necessarily involves facilitation by intrinsic membrane transport proteins. The functional characterization and categorization of membrane transport proteins was a major focus of cell physiological research from the 1950s through the 1980s. On the basis of these functional analyses, ion transport proteins were broadly divided into two classes: channels and carrier-type transporters (which include exchangers, cotransporters, and ATP-driven ion pumps). Beginning in the mid-1980s, these functional analyses of ion transport and homeostasis were complemented by the cloning of genes encoding many ion channels and transporter proteins. Comparison of the predicted primary amino acid sequences and structures of functionally similar ion transport proteins facilitated their grouping within families and superfamilies of structurally related membrane proteins. Postgenomics research in ion transport biology increasingly involves two powerful approaches. One involves elucidation of the molecular structures, at the atomic level in some cases, of model ion transport proteins. The second uses the tools of cell biology to explore the cell-specific function or subcellular localization of ion transport proteins. This review will describe how these approaches have provided new, and sometimes surprising, insights regarding four major questions in current ion transporter research. 1) What are the fundamental differences between ion channels and ion transporters? 2) How does the interaction of an ion transport protein with so-called adapter proteins affect its subcellular localization or regulation by various intracellular signal transduction pathways? 3) How does the specific lipid composition of the local membrane microenvironment modulate the function of an ion transport protein? 4) How can the basic functional properties of a ubiquitously expressed ion transport protein vary depending on the cell type in which it is expressed?

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