scholarly journals Physiological roles of nicotinamide nucleotide transhydrogenase

1988 ◽  
Vol 254 (1) ◽  
pp. 1-10 ◽  
Author(s):  
J B Hoek ◽  
J Rydström
Keyword(s):  
Redox Potential ◽  
Buffer System ◽  
Emergency Protection ◽  
High Demand ◽  
Energy Depletion ◽  
Flexible Element ◽  
Metabolic Conditions ◽  
Effective Buffer ◽  
Kinetic Features ◽  
Reducing Equivalents

From the foregoing considerations, the energy-linked transhydrogenase reaction emerges as a powerful and flexible element in the network of redox and energy interrelationships that integrate mitochondrial and cytosolic metabolism. Its thermodynamic features make it possible for the reaction to respond readily to challenges, either on the side of NADPH utilization or on the side of energy depletion. Yet, the kinetic features are designed to prevent a wasteful input of energy when other sources of reducing equivalents to NADP are available, or to deplete the redox potential of NADPH in other than emergency conditions. By virtue of these characteristics, the energy-linked transhydrogenase can act as an effective buffer system, guarding against an excessive depletion of NADPH, preventing uncontrolled changes in key metabolites associated with NADP-dependent enzymes and calling on the supply of reducing equivalents from NAD-linked substrates only under conditions of high demand for NADPH. At the same time, it can provide an emergency protection against a depletion of energy, especially in situations of anoxia where a supply of reducing equivalents through NADP-linked substrates can be maintained. The flexibility of this design makes it possible that the functions of the energy-linked transhydrogenase vary from one tissue to another and are readily adjustable to different metabolic conditions.

Quantifying salt sensitivity

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hans Oberleithner
Keyword(s):  
Organ Damage ◽  
Salt Sensitivity ◽  
Buffering Capacity ◽  
Buffer System ◽  
Protective Film ◽  
Simple Method ◽  
Salt Consumption ◽  
Long Run ◽  
Positively Charged ◽  
Effective Buffer

Abstract Inner surfaces of blood vessels and outer surfaces of erythrocytes are coated with a negatively charged protective film of proteoglycans, which serves as an effective buffer system for the positively charged sodium ions. If this protective coating is poorly developed or impaired, it loses its buffering capacity. As a consequence, the organism becomes increasingly sensitive to sodium, which in the long run leads to organ damage, especially if daily salt consumption is high. Recently, it has become possible to quantify salt sensitivity using a technically simple method – the salt blood test (SBT). Aim of this mini-review is to explain the physiological concept underlying the SBT and its potential practical relevance in the prevention of cardiovascular disease.

The hyperpolarizing effect of hydrogen ions on transmembrane potential in frog skeletal muscle

1968 ◽  
Vol 46 (2) ◽  
pp. 151-157 ◽  
Author(s):  
G. W. Mainwood ◽  
S. L. Lee
Keyword(s):  
Transmembrane Potential ◽  
Ph Effect ◽  
Cell Activity ◽  
Ringer Solution ◽  
Buffer System ◽  
Hydrogen Ions ◽  
Transmembrane Conductance ◽  
Metabolic Conditions ◽  
External Potassium ◽  
Hyperpolarizing Response

The transmembrane potential of frog sartorius fibers in normal Ringer's solution is increased by a few millivolts following a fall in pH of the external medium. The same result is observed in either a bicarbonate–CO2 or a phosphate buffer system. The hyperpolarizing response is still observed when sodium in the Ringer solution is replaced by choline. Immediately after increasing the external potassium from 2.5 to 10 meq/l this effect is reversed. On changing the external potassium back to 2.5 meq/l the effect returns and is considerably enhanced. Chloride loading by presoaking muscles in isotonic KCl and transferring to sucrose causes a reversal of membrane potential and leads to an exaggerated pH effect. These observations, together with the fact that transmembrane conductance falls at a lower pH, suggest that hydrogen ions act mainly by lowering PCl. When ECl > Em, hydrogen ions will increase transmembrane potential. This effect may form the basis of a local control mechanism by which cell activity and local metabolic conditions regulate transmembrane potential.

Redox potential of the small intestine lumer in a model of experimental hemorrhage in rats

2001 ◽  
Vol 120 (5) ◽  
pp. A195-A195
Author(s):  
J PAULA ◽  
E SPINEDI ◽  
A DUBIN ◽  
D BUSTOS ◽  
J DAVOLOS
Keyword(s):  
Small Intestine ◽  
Redox Potential

Fibrin Formation: The Role of the Fibrinogen-Fibrin Monomer Complex

1976 ◽  
Vol 36 (01) ◽  
pp. 037-048 ◽  
Author(s):  
Eric P. Brass ◽  
Walter B. Forman ◽  
Robert V. Edwards ◽  
Olgierd Lindan
Keyword(s):  
Particle Size ◽  
Induction Period ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Appreciable Amount ◽  
Buffer System ◽  
Homeostatic Mechanism ◽  
Fibrin Formation ◽  
Fibrin Monomer

SummaryThe process of fibrin formation using highly purified fibrinogen and thrombin was studied using laser fluctuation spectroscopy, a method that rapidly determines particle size in a solution. Two periods in fibrin clot formation were noted: an induction period during which no fibrin polymerization occurred and a period of rapid increase in particle size. Direct measurement of fibrin monomer polymerization and fibrinopeptide release showed no evidence of an induction period. These observations were best explained by a kinetic model for fibrin clot formation incorporating a reversible fibrinogen-fibrin monomer complex. In this model, the complex serves as a buffer system during the earliest phase of fibrin formation. This prevents the accumulation of free polymerizable fibrin monomer until an appreciable amount of fibrinogen has reacted with thrombin, at which point the fibrin monomer level rises rapidly and polymerization proceeds. Clinically, the complex may be a homeostatic mechanism preventing pathological clotting during periods of elevated fibrinogen.

Human Blood Platelet Membrane Glycoproteins

1979 ◽  
Vol 42 (05) ◽  
pp. 1490-1502 ◽  
Author(s):  
C S P Jenkins ◽  
E F Ali-Briggs ◽  
G T E Zonneveld ◽  
A Sturk ◽  
J Clemetson
Keyword(s):  
Specific Problem ◽  
Sodium Dodecyl ◽  
Normal Subjects ◽  
Blood Platelet ◽  
Platelet Membrane ◽  
Buffer System ◽  
Membrane Glycoprotein ◽  
Membrane Glycoproteins ◽  
Human Blood Platelet ◽  
Electrophoretic Techniques

SummaryThe separation of the major platelet membrane glycoproteins of normal subjects and subjects with well defined platelet membrane glycoprotein abnormalities have been examined using four different polyacrylamide gel electrophoretic techniques (continuous and discontinuous). The mobilities of the resolved glycoprotein bands have been correlated with the glycoprotein nomenclature proposed for the conventional sodium dodecyl sulphate- phosphate buffer system. Since the glycoprotein distribution varies depending on the system used, the merits of each method should be considered before application to a specific problem.

Tomato Production in Florida Using Fertigation Technology

EDIS ◽  
2020 ◽  
Vol 2020 (5) ◽  
Author(s):  
Mary Dixon ◽  
Guodong Liu
Keyword(s):  
Nutrient Use Efficiency ◽  
Health Benefits ◽  
Vegetable Crop ◽  
High Demand ◽  
Tomato Production ◽  
Nutrient Use ◽  
Use Efficiency

Tomato is in high demand because of its taste and health benefits. In Florida, tomato is the number one vegetable crop in terms of both acreage and value. Because of its high value and wide acreage, it is important for tomato production to be efficient in its water and nutrient use, which may be improved through fertigation practices. Therefore, the objective of this new 7-page article is to disseminate research-based methods of tomato production utilizing fertigation to enhance yield and nutrient use efficiency. Written by Mary Dixon and Guodong Liu, and published by the UF/IFAS Horticultural Sciences Department.https://edis.ifas.ufl.edu/hs1392

Recent trends in Component Based software development and Efficiency analysis of Semantic search based component retrieval Technique

2018 ◽  
pp. 105-113 ◽  
Author(s):  
Vishnu Sharma ◽  
Vijay Singh Rathore
Keyword(s):  
Software Development ◽  
Efficiency Analysis ◽  
Software Components ◽  
High Demand ◽  
Component Retrieval ◽  
Software Developer ◽  
Software Libraries ◽  
Retrieval Technique ◽  
Executable File ◽  
Recent Trends

In these days most of the software development uses preexisting software components. This approach provides plenty of benefits over the traditional development. Most of the software industries uses their own domain based software libraries where components resides in the form of modules, codes, executable file, documentations, test plans which may be used as it is or with minor changes. Due to shrinking time and high demand of software development it is necessary to use pre tested software components to ensure high functionality in software developed. Software components can be used very easily and without having the worries of errors and bugs because these are developed under expert supervision and well tested. What we have to do is just embed these components in our project. In this paper a survey got conducted over 112 software developer,testers and freelancers. In survey several issues in CBSD were identified. An efficient repository along with a component search engine is developed. All the component retrieval techniques were evaluated and compared with precise and recall method.

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