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Development and Utilization of a Novel Prodosomed-Electrolyte and Phytochemical Formulation Technology to Restore Metabolic Homeostasis
Published in Debasis Bagchi, Manashi Bagchi, Metal Toxicology Handbook, 2020
Bernard W. Downs, Manashi Bagchi, Bruce S. Morrison, Jeffrey Galvin, Steve Kushner, Debasis Bagchi
Sodium: Electrolytes carry an electrical charge specifically when it is dissolved in body fluids including blood. Accordingly, sodium is mainly located in blood and in the fluid around the cells.32,33 The key roles of sodium are to maintain normal nerve and muscle functions and maintain the homeostatic properties of body fluids.33–35 Food and drink are the major dietary source of sodium intake, while sweat and urine facilitate sodium loss from the human body. Sodium regulates the amount of fluid in blood and around cells.32–36 Sodium is moved across cell membranes by the sodium–potassium pump, an enzyme also known as sodium/potassium ATPase. Moreover, the kidney acts as a prime regulator of good health by regulating hydroxyl ion exchange (onto CO2 to make HCO3 [bicarbonate] and off HCO3 to make CO2) to maintain the ideal blood pH.32–37 In addition, the kidneys maintain a consistent level of sodium balance in the human body by regulating urinary excretion of sodium from the body. However, when sodium balance gets disrupted due to pathophysiological influences then the concentration of sodium in the blood may be too low (hyponatremia) or too high (hypernatremia).32–37
Electric Activities of the Cell
Published in Kayvan Najarian, Robert Splinter, Biomedical Signal and Image Processing, 2016
Kayvan Najarian, Robert Splinter
As can be seen from the definition of the Nernst potentials, the main factor in maintaining the Nernst potentials the same of each ion is ensuring that the concentration of the intercellular and extracellular fluids for each ion are constant. As mentioned earlier, the sodium–potassium pump has a central role in maintaining the concentration of the ions therefore maintaining the transmembrane voltage. This pump essentially exchanges potassium for sodium from extra- to intracellular fluid in a 2:3 ratio, respectively.
39K
Published in Guillaume Madelin, X-Nuclei Magnetic Resonance Imaging, 2022
As for sodium, potassium concentrations in cells are therefore very sensitive to changes in the metabolic state of tissues and the integrity of cell membranes. The potassium influx and outflux in cells can occur by several routes, such as voltage-gated K+ channels (which are the most widely distributed type of ion channel and are found in almost all living organisms), the Na+/Ca2+-K+ exchanger, the Na+-K+/2Cl− and K+-Cl− cotransporters, and, most importantly, through the Na+/K+-ATPase. The Na+/K+-ATPase (also called sodium–potassium pump) is present within the membrane of every animal cell. It is a plasma membrane-associated protein complex that is expressed in most eukaryotic cells and can be considered either an enzyme (ATPase) or an ion transporter. Its main function is to maintain the sodium and potassium gradients across the membrane by pumping three intracellular sodium ions out of the cell and two extracellular potassium ions within the cell. This ion transport is performed against the electrochemical Na+ and K+ gradients existing across the cell membrane and therefore requires energy, provided by adenosine triphosphate (ATP) hydrolysis. These high electrochemical sodium and potassium gradients are essential to protect the cell from bursting as a result of osmotic swelling. They regulate the cell volume and help maintain the resting cell membrane potential that can be used for transmitting nerve impulses (Na+ and K+ have to be actively pumped back after an excitation event of a nerve or muscle membrane potential) and for pumping ions (protons, calcium, chloride, phosphate), metabolites (glucose, amino acids), or neurotransmitters (glutamate) across the cell membrane. Regulation of Na+/K+-ATPase therefore plays a key role in the etiology of some pathological processes. When the demand for ATP exceeds its production (when cell membrane leaks overwhelm the pumping capacity), the ATP supply for the Na+/K+-ATPase will be insufficient to maintain the electrochemical potassium gradient and thus a variation of intracellular potassium concentration can be observed, leading to changes in osmolarity and eventually leading to cell death. Typical concentrations of potassium in the human body are listed in Table 6.2.
Mathematical modeling of the cardiac tissue
Published in Mechanics of Advanced Materials and Structures, 2022
The exchange of sodium and potassium ions, which determines the calcium regulation of actomyosin conjugation, is called a sodium-potassium pump. It is provided by the enzyme adenosine triphosphates membranes of cardiomyocytes which, in turn, is regulated by subtle biochemical reactions. The sodium-potassium pump maintains high values of the resting potential at a stable level, which is crucial in ensuring the function of myocardial contractility. To maintain it, it is necessary that the cardiac current leaving the cardiomyocyte be equal in magnitude and opposite in the direction of the sodium current. The excess of the incoming current above the output determines the magnitude of the action potential and the rate of its growth, which regulates calcium fluxes and, as a result, the process of actomyosin conjugation.
Characterization of surface modified glycerol/silk fibroin film for application to corneal endothelial cell regeneration
Published in Journal of Biomaterials Science, Polymer Edition, 2019
Jeong Eun Song, Bo Ra Sim, Yoo Shin Jeon, Han Sol Kim, Eun Yeong Shin, Cristiano Carlomagno, Gilson Khang
Figure 4 shows the rCEnCs expression pattern for NaK, AQ1, and CLCN3 when seeded on SF, 1 and 3% G/SF films. From electrophoretic results, all the genes were expressed from cells seeded on both the samples (Figure 4a). The quantitative expression result, normalized with the β-actin gene, confirm the previous result. In other word, 1% G/SF film showed the highest rate in all gene expressions among the other groups (Figure 4b). No significant differences in the gene expression pattern of cells in contact with films were noticed. The expression of NaK, AQ1, and CLCN3 is fundamental for the maintenance of tissue functions. NaK is a sodium potassium pump located on the CEnC surface. The principal pump role is to control corneal hydration and transparency regulating the water permeability from the corneal stroma. AQ1 is a transport protein also involved in the regulation of the tissue hydrated state, while, CLCN3 is a H+/Cl− exchange transporter which regulates the shape and size of the cells [13]. A correct expression of these genes is fundamental for the physiological functions of the corneal tissue. The presence of glycerol doesn’t affect the expression patter making the material potentially suitable for cornea transplantation.
Electrocardiogram signal generation using electrical model of cardiac cell: application in cardiac ischemia
Published in Journal of Medical Engineering & Technology, 2019
Alireza Fallahi, Hamidreza Ghanbari Khorram, Alireza Kokabi
Phase 2 is sustained by a balance between the inward movement of Ca2+ ions, ICa, through L-type calcium channels and outward movement of K+ ions through the slow delayed rectifier potassium channels, IK. The sodium-calcium exchanger current, INaCa, and the sodium/potassium pump current, INaK, also play minor roles during Phase 2.