scholarly journals The antagonistic action of calcium upon the inhibitory effort of magnesium

1908 ◽  
Vol 80 (539) ◽  
pp. 260-261 ◽  
Keyword(s):  
Inhibitory Effect ◽  
Inhibitory Influence ◽  
Intracerebral Injection ◽  
Physiological Effects ◽  
American Physiological Society ◽  
Antagonistic Action ◽  
Animal Body ◽  
Magnesium Salts ◽  
Calcium And Magnesium ◽  
Prevailing View

Calcium and magnesium are chemically closely related elements. They are also close companions in the tissues of the animal body. It is the prevailing view that the physiological effects of both elements are similar in character. Many physiologists are at present of the opinion that calcium as well as magnesium exerts an inhibitory influence in the functions of the animal body. Loeb published, in 1899, his observations of the inhibitory action of calcium upon the twitchings of the frog muscles brought on by solutions of sodium chloride. It was then assumed by Loeb that all the members of the group of alkali earths possess inhibitory properties, including, at first, even barium. In the numerous subsequent papers by Lob and his pupils, the discussion turned, however, essentially around the inhibitory effect of calcium. As to magnesium, we have within the last few years published several studies in support of the hypothesis that magnesium salts favour inhibitory processes. The first fact which gave rise to that hypothesis was demonstrated in 1899 to the American Physiological Society. When an intracerebral injection of a few drops of a solution of magnesium sulphate caused a state of paralysis in a rabbit, while the injection of other solutions brought on convulsions.

Influence of Codisposal of Municipal Solid Waste and Olive Vegetation Water on the Anaerobic Digestion of a Sanitary Landfill

1993 ◽  
Vol 27 (2) ◽  
pp. 261-271 ◽  
Author(s):  
R. Cossu ◽  
N. Blakey ◽  
P. Cannas
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Research Study ◽  
Inhibitory Effect ◽  
Organic Load ◽  
Sanitary Landfill ◽  
Inhibitory Influence ◽  
Vegetation Water ◽  
Waste Degradation ◽  
Very High

A research study was carried out aiming to investigate the possibility of treatment of vegetation water in a anaerobic digester like a sanitary landfill. This vegetation water originates from olive oil production. The results, obtained from lysimeters filled with Municipal Solid Waste, show very high gasification and reduction of the organic load of vegetation water, with no inhibitory effect on waste degradation processes providing the vegetation water is added to an active methanogenic system or buffering the landfill system during the acid phase. The inhibitory influence of compounds, like polyphenols, which can be present in vegetation water in large amounts, has been studied.

scholarly journals The metabolism of amiodarone by various CYP isoenzymes of human and rat, and the inhibitory influence of ketoconazole

2008 ◽  
Vol 11 (1) ◽  
pp. 147 ◽  
Author(s):  
Marwa E. Elsherbiny ◽  
Ayman O.S. El-Kadi ◽  
Dion R. Brocks
Keyword(s):  
Cytochrome P450 ◽  
Inhibitory Effect ◽  
Intrinsic Clearance ◽  
Significant Inhibition ◽  
Inhibitory Influence ◽  
Relative Kinetic ◽  
Cyp Isoforms ◽  
High Concentrations ◽  
In Vivo Administration

PURPOSE. To evaluate the metabolism of amiodarone (AM) to desethylamiodarone (DEA) by selected human and rat cytochrome P450, and the inhibitory effect of ketoconazole (KTZ). METHODS. Some important CYP isoenzymes (rat CYP1A1, 1A2, 2C6, 2C11, 2D1, 2D2, and 3A1 and human CYP1A1, 1A2, 2D6 and 3A4) were spiked with various concentrations of AM to determine the relative kinetic parameters for formation of DEA in the presence and absence of various concentrations of KTZ. RESULTS. The formation of DEA was observed when AM was exposed to each of the CYP tested, although the rates were varied. Human CYP1A1 followed by 3A4 had the highest intrinsic clearance (CLint) for DEA formation whereas in rat, CYP2D1 followed by CYP2C11 had the highest CLint. Human and rat CYP1A2 seemed to have the lowest CLint. At high concentrations of AM and KTZ, near those expected in vivo, significant inhibition of all isoforms except for rat CYP1A2 was observed. At lower concentration ranges of both drugs, the inhibitory constant was determined. At these levels, KTZ was found to potently inhibit human CYP1A1 and 3A4 and rat 2D2 and 1A1. CONCLUSION. Human CYP1A1 and 3A4 and rat CYP2D1 and 2C11 were most efficient in converting AM to DEA. For DEA formation, the in vivo administration of KTZ could inhibit other CYP isoforms besides CYP3A in human and rat.

scholarly journals Reasons for Reduced Moisture Resistance of Sulfur-Extended Asphalt Concrete

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7218
Author(s):  
Huu Tuan Le ◽  
Evgenij V. Korolev ◽  
Anna N. Grishina ◽  
Vitaly A. Gladkikh
Keyword(s):  
Asphalt Concrete ◽  
Water Soluble ◽  
Moisture Resistance ◽  
Physical Processes ◽  
Capillary Structure ◽  
Hydrolytic Decomposition ◽  
Magnesium Salts ◽  
Calcium And Magnesium ◽  
Sulfur Containing ◽  
Decomposition Of Water

The paper presents the results of a study of the mechanism for reducing the moisture resistance of sulfur-extended asphalt concrete. It is shown that a decrease in moisture resistance occurs due to the occurrence of chemical and physical processes. At the same time, it was found that during the manufacture of sulfur-bitumen composites, toxic gases H2S and SO2 are formed, which are capable of interacting with a mineral filler, as well as the interaction of sulfur with a mineral powder with the formation of sulfur-containing water-soluble salts, the extraction of which leads to a decrease in the moisture resistance of sulfur-bitumen materials. The change in the rate of leaching of these substances from the composite is due to the physical process caused by the crystallization of sulfur and the formation of a capillary structure, which significantly increases the rate of leaching of calcium and magnesium salts, which are products of dissolution or hydrolytic decomposition of water-soluble products of the interaction of sulfur, H2S and SO2 gases with calcium and magnesium carbonates. The intensity of chemical and physical processes intensifies with an increase in the amount of sulfur in sulfur-bitumen materials.

Cardioregulatory properties of the abdominal ganglia in Limulus

1970 ◽  
Vol 48 (6) ◽  
pp. 333-341 ◽  
Author(s):  
R. Von Burg ◽  
W. C. Corning
Keyword(s):  
Central Nervous System ◽  
Heart Rate ◽  
Nervous System ◽  
Heart Function ◽  
Inhibitory Effect ◽  
Bioelectrical Activity ◽  
Inhibitory Influence ◽  
Dorsal Nerves

The abdominal ganglia of the Limulus central nervous system exert a net inhibitory effect on heart rate. This influence is mediated mainly by the dorsal nerves in the first three ganglia. When the dorsal nerves are sectioned, cardioacceleration results; when these nerves are stimulated, a reduction in rate is obtained. However, cardioaccelerators can be unmasked by splitting a ganglion. This selectively removes the inhibitory output, leaving only a cardioaccelerator influence. Inhibition of bioelectrical activity in the intact abdominal ganglia with GABA also resulted in an increased heart rate, confirming their net inhibitory influence on heart function. Possible models of abdominal ganglia organization are discussed.

Production and bioavailability of calcium and magnesium salts of omega-3 fatty acids

2009 ◽  
Vol 1 (2) ◽  
pp. 217-221 ◽  
Author(s):  
Jaroslav A. Kralovec ◽  
H. Stephen Ewart ◽  
Jeffrey H.D. Wright ◽  
Lynn V. Watson ◽  
Dorothy Dennis ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Omega 3 Fatty Acids ◽  
Omega 3 ◽  
Magnesium Salts ◽  
Calcium And Magnesium

scholarly journals Inhibitory effect of alcohol on ghrelin secretion in normal man

2005 ◽  
Vol 152 (5) ◽  
pp. 743-747 ◽  
Author(s):  
Jan Calissendorff ◽  
Olle Danielsson ◽  
Kerstin Brismar ◽  
Sven Röjdmark
Keyword(s):  
Drinking Water ◽  
Venous Blood ◽  
Serum Levels ◽  
Underlying Mechanism ◽  
Inhibitory Effect ◽  
Inhibitory Influence ◽  
Normal Man ◽  
Obese Subjects ◽  
Ghrelin Secretion ◽  
Serum Ghrelin

Background: Human appetite is stimulated by alcohol but the underlying mechanism is unknown. It is possible that hunger-stimulating hormones are mediators of this effect of alcohol. Ghrelin stimulates hunger, but how alcohol affects human ghrelin secretion has never been studied before. Objective: To investigate whether alcohol ingestion exerts an acute influence on serum ghrelin concentrations in healthy subjects. Subjects and design: Eight healthy non-obese subjects participated in the study. All were investigated on two occasions (experiments A and B). Alcohol (0.55 g ethanol/kg body weight) was ingested in experiment A, and drinking-water in experiment B. Venous blood was collected before, and 30 and 60 min after consumption of the drinks. Serum concentrations of ghrelin, cortisol and ethanol were determined and neuropeptide Y (NPY) concentrations were determined in plasma. Results: Alcohol lowered the ghrelin level by 13.9±5.0% at 30 min and by 17.5±2.6% at 60 min, in contrast to drinking-water which was without significant effect. Serum levels of cortisol and insulin were similar after alcohol and water as was plasma NPY. Conclusion: Alcohol has an acute inhibitory influence on human ghrelin secretion but no measurable effect on the secretion of NPY and cortisol. Hence, none of these hormones mediate the orexigenic effect of the drug.

A functional analysis of dopaminergic innervation of the neurohypophysis

1981 ◽  
Vol 241 (3) ◽  
pp. E186-E190
Author(s):  
S. S. Passo ◽  
J. R. Thornborough ◽  
C. F. Ferris
Keyword(s):  
Functional Analysis ◽  
Electrical Activity ◽  
Dopaminergic Neurons ◽  
Arcuate Nucleus ◽  
Inhibitory Effect ◽  
Inhibitory Influence ◽  
Dopamine Receptor Antagonist ◽  
Neurohypophyseal Hormones ◽  
Stimulus Train ◽  
Stimulation Of

Dopaminergic neurons arising from cell bodies in the rostral arcuate nucleus of the hypothalamus have been shown to make axoaxonic contact with neurohypophyseal neurosecretory axons. In this study, electrical stimulation of the rostral arcuate nucleus depresses multiunit electrical activity recorded from neurosecretory axons within the neurohypophysis. After a single 5-s stimulus train, neurohypophyseal electrical activity is reduced to 6% of control. The superfusion of dopamine (5 micrograms/microliters) onto the neurohypophysis also has an inhibitory effect. Superfusion directly onto the neurohypophysis of the dopamine-receptor antagonist, pimozide (1 micrograms/microliters), abolishes the inhibitory effect of arcuate nucleus stimulation. These findings suggest that the dopaminergic innervation of the neurohypophysis may have an inhibitory influence on the release of neurohypophyseal hormones.

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