scholarly journals Effects of hydrostatic pressure on membrane processes. Sodium channels, calcium channels, and exocytosis.

1987 ◽  
Vol 90 (6) ◽  
pp. 765-778 ◽  
Author(s):  
S H Heinemann ◽  
F Conti ◽  
W Stühmer ◽  
E Neher
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
High Pressures ◽  
Mean Amplitude ◽  
National Academy Of Sciences ◽  
Na Currents ◽  
Experimental Resolution ◽  
Adrenal Chromaffin ◽  
Academy Of Sciences ◽  
Ca Currents

A patch-clamp study under high hydrostatic pressure was performed by transferring cells or membrane patches into a pressure vessel (Heinemann, S. H., W. Stühmer, and F. Conti, 1987, Proceedings of the National Academy of Sciences, 84:3229-3233). Whole-cell Na currents as well as Ca currents were measured at pressures up to 40 MPa (approximately 400 atm; 1 MPa = 9.87 atm) in bovine adrenal chromaffin cells. Ca currents were found to be independent of pressure within experimental resolution. The mean amplitude and the gating kinetics of Na currents were affected by less than 20% at 10 MPa. This lack of a pronounced effect is surprising since the high-pressure nervous syndrome (HPNS), a disorder at high pressures known to result from impaired nervous transmission, manifests itself at pressures as low as 5 MPa. The results show that ion channels involved in transmission cannot be implicated in HPNS. However, when exocytosis was studied at high pressure by monitoring the cell capacitance (Neher, E., and A. Marty, 1982, Proceedings of the National Academy of Sciences, 79:6712-6716), more drastic effects were seen. The degranulation evoked by dialyzing the cell with 1 microM free Ca2+ could be slowed by a factor of 2 by application of 10 MPa. The same effect was observed for the degranulation of rat peritoneal mast cells stimulated with 40 microM of the GTP analogue GTP-gamma-S. According to these results, the process of exocytosis is the most likely site at which hydrostatic pressure can act to produce nervous disorders. Furthermore, we demonstrate that pressure can be a useful tool in the investigation of other cellular responses, since we were able to separate different steps occurring during exocytosis owing to their different activation volumes.

scholarly journals Evaluating the Anti-Inflammatory and Antioxidant Effects of Broccoli Treated with High Hydrostatic Pressure in Cell Models

Foods ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 167
Author(s):  
Yi-Yuan Ke ◽  
Yuan-Tay Shyu ◽  
Sz-Jie Wu
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
High Pressures ◽  
High Pressure Processing ◽  
Total Phenolic ◽  
Anti Inflammatory ◽  
Functional Components ◽  
Antioxidant Effects ◽  
Myrosinase Activity

Isothiocyanates (ITCs) are important functional components of cruciferous vegetables. The principal isothiocyanate molecule in broccoli is sulforaphane (SFN), followed by erucin (ERN). They are sensitive to changes in temperature, especially high temperature environments where they are prone to degradation. The present study investigates the effects of high hydrostatic pressure on isothiocyanate content, myrosinase activity, and other functional components of broccoli, and evaluates its anti-inflammatory and antioxidant effects. Broccoli samples were treated with different pressures and for varying treatment times; 15 min at 400 MPa generated the highest amounts of isothiocyanates. The content of flavonoids and vitamin C were not affected by the high-pressure processing strategy, whereas total phenolic content (TPC) exhibited an increasing tendency with increasing pressure, indicating that high-pressure processing effectively prevents the loss of the heat-sensitive components and enhances the nutritional content. The activity of myrosinase (MYR) increased after high-pressure processing, indicating that the increase in isothiocyanate content is related to the stimulation of myrosinase activity by high-pressure processing. In other key enzymes, the ascorbate peroxidase (APX) activity was unaffected by high pressure, whereas peroxidase (POD) and polyphenol oxidase (PPO) activity exhibited a 1.54-fold increase after high-pressure processing, indicating that high pressures can effectively destroy oxidases and maintain food quality. With regards to efficacy evaluation, NO production was inhibited and the expression levels of inducible nitric oxide synthase (iNOS) and Cyclooxygenase-2 (COX-2) were decreased in broccoli treated with high pressures, whereas the cell viability remained unaffected. The efficacy was more significant when the concentration of SFN was 60 mg·mL−1. In addition, at 10 mg·mL−1 SFN, the reduced/oxidized glutathione (GSH/GSSG) ratio in inflammatory macrophages increased from 5.99 to 9.41. In conclusion, high-pressure processing can increase the isothiocyanate content in broccoli, and has anti-inflammatory and anti-oxidant effects in cell-based evaluation strategies, providing a potential treatment strategy for raw materials or additives used in healthy foods.

scholarly journals Molecular Responses to High Hydrostatic Pressure in Eukaryotes: Genetic Insights from Studies on Saccharomyces cerevisiae

Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1305
Author(s):  
Fumiyoshi Abe
Keyword(s):  
Saccharomyces Cerevisiae ◽  
High Pressure ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
High Pressures ◽  
Strong Association ◽  
Pressure Effects ◽  
Basic Knowledge ◽  
Challenger Deep ◽  
Human Joints

High hydrostatic pressure is common mechanical stress in nature and is also experienced by the human body. Organisms in the Challenger Deep of the Mariana Trench are habitually exposed to pressures up to 110 MPa. Human joints are intermittently exposed to hydrostatic pressures of 3–10 MPa. Pressures less than 50 MPa do not deform or kill the cells. However, high pressure can have various effects on the cell’s biological processes. Although Saccharomyces cerevisiae is not a deep-sea piezophile, it can be used to elucidate the molecular mechanism underlying the cell’s responses to high pressures by applying basic knowledge of the effects of pressure on industrial processes involving microorganisms. We have explored the genes associated with the growth of S. cerevisiae under high pressure by employing functional genomic strategies and transcriptomics analysis and indicated a strong association between high-pressure signaling and the cell’s response to nutrient availability. This review summarizes the occurrence and significance of high-pressure effects on complex metabolic and genetic networks in eukaryotic cells and how the cell responds to increasing pressure by particularly focusing on the physiology of S. cerevisiae at the molecular level. Mechanosensation in humans has also been discussed.

Characteristics of Low- and High-Fat Beef Patties: Effect of High Hydrostatic Pressure

1997 ◽  
Vol 60 (1) ◽  
pp. 48-53 ◽  
Author(s):  
J. CARBALLO ◽  
P. FERNANDEZ ◽  
A. V. CARRASCOSA ◽  
M. T. SOLAS ◽  
F. JIMENEZ COLMENERO
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Shear Force ◽  
High Pressures ◽  
Lethal Effect ◽  
High Fat ◽  
Low Fat ◽  
Binding Properties ◽  
Beef Patties

The purpose of this study was to analyze the consequences of applying high pressures (100 and 300 MPa for 5 or 20 min) on characteristics such as water- and fat-binding properties, texture, color, microstructure, and microbiology of low-fat (9.2%) and high-fat (20.3%) beef patties. In nonpressurized patties, the low-fat product exhibited significantly poorer (P < 0.05) binding properties and higher (P < 0.05) Kramer shear force and Kramer energy than did high-fat patties. Although high pressure did not clearly influence the binding properties of low- and high-fat beef patties, it did produce a rise in the Kramer shear force and energy which were more pronounced at 300 MPa. High pressures altered patty color, the extent of alteration depending on fat content, pressure, and pressurizing time. Pressurizing high- and low-fat beef patties at 300 MPa not only produced a lethal effect (P < 0.05) on microorganisms, but caused sublethal damage as well.

Doping dependence of semiconductor–metal transition in InP at high pressures

1986 ◽  
Vol 405 (1829) ◽  
pp. 345-353 ◽  
Keyword(s):  
High Pressure ◽  
Liquid Phase ◽  
Hydrostatic Pressure ◽  
Doping Concentration ◽  
High Pressures ◽  
Metallic Phase ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Transition Pressure ◽  
High Concentrations

The resistivity of selenium-doped n-InP single crystal layers grown by liquid-phase epitaxy with electron concentrations varying from 6.7×10 18 to 1.8×10 20 cm -3 has been measured as a function of hydrostatic pressure up to 10 GPa. Semiconductor-metal transitions were observed in each case with a change in resistivity by two to three orders of magnitude. The transition pressure p c decreased monotonically from 7.24 to 5.90 GPa with increasing doping concentration n according to the relation p c = p o [1 - k ( n / n m ) α ], where n m is the concentration (per cubic centimetre) of phosphorus donor sites in InP atoms, p o is the transition pressure at low doping concentrations, k is a constant and α is an exponent found experimentally to be 0.637. The decrease in p c is considered to be due to increasing internal stress developed at high concentrations of ionized donors. The high-pressure metallic phase had a resistivity (2.02–6.47)×10 -7 Ω cm, with a positive temperature coefficient dependent on doping.

scholarly journals Influence of high pressure on amino acids and their multicomponent crystals

2014 ◽  
Vol 70 (a1) ◽  
pp. C1192-C1192
Author(s):  
Boris Zakharov ◽  
Elena Boldyreva ◽  
Boris Kolesov ◽  
Evgeniy Losev ◽  
Sergey Arkhipov
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
High Pressure ◽  
Phase Transitions ◽  
Crystal Structures ◽  
High Pressures ◽  
Ministry Of Education ◽  
Amino Acid Salts ◽  
The Individual ◽  
Academy Of Sciences

The studies of molecular crystals at high pressures help to understand intermolecular interactions, their role in the formation of crystal structures and in crystal structure response to external actions. Multicomponent crystals are promising for high-pressure research since a large number of phenomena has been observed for them [1]. Crystals of amino acids, their salts and co-crystals are of special interest in this respect. They are promising as new materials and can serve as biomimetics since the structure forming units of these crystals are similar to those in biomolecules. The aim of this study was to follow the effect of increasing pressure on crystal structures of amino acid salts and co-crystals to compare the results with those obtained for individual amino acids. Glycine, alanine, serine and their corresponding salts with carboxylic acids were chosen as objects of the study. Single-crystal X-ray diffraction and Raman spectroscopy were used as main experimental techniques. Three different types of behavior of salts on increasing pressure as compared with individual crystals were observed. For some salts, adding the second component stabilized the crystal structure with respect to phase transitions [2]. In the second group, on the contrary, the salts underwent phase transitions at relatively low pressures, though individual components did not undergo phase transitions at least up to 8-10 GPa. The last, third group of salts showed phase transitions in a similar pressure range as the individual components, but the mechanism of the transition changed. The phase transitions were accompanied either by crystal structure disordering, or by switching-over hydrogen bonds [3]. This work was supported by a grant from RFBR (12-03-31541 mol_a), by the Ministry of Education and Science of Russia, Russian Academy of Sciences, and by a grant of President of Russia for State support of Russian leading Scientific Schools (project NSh-279.2014.3).

Very High Pressure Generation at the Deep Sea

1983 ◽  
Vol 22 ◽  
Author(s):  
Kaichi Suito ◽  
Katsumi Yasukawa
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Natural Resources ◽  
Deep Sea ◽  
High Pressures ◽  
Large Area ◽  
High Pressure Apparatus ◽  
Very High

ABSTRACTIn the deep sea, truely hydrostatic pressure is produced in a very large area. This pressure may be used as natural resources. By utilizing these resources, very high pressures can be generated using a 6–8 type split-sphere high pressure apparatus. A preliminary experiment to generate very high pressure was undertaken in the deep sea at a depth of about 1000 m. Pressures of about 8.5 GPa were generated in the central part of the high pressure apparatus.

High Pressure Testing Hazards

2009 ◽  
Author(s):  
Matthew Edel ◽  
Donald Ketchum ◽  
Jasen Falcon
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Pressure Vessel ◽  
High Pressures ◽  
Pressure Vessels ◽  
Blast Loads ◽  
Pressure Testing ◽  
Safety Research ◽  
Back Face

Pressure vessels that operate at high pressures (greater than 10,000 psi [69 MPa]) pose several potential hazards to nearby personnel. Some of these hazards include projectile launch, water jetting, and blast loads that may occur as a result of a pneumatic or hydrostatic pressure vessel failure. In order to provide personnel protection, pressure vessels may be placed inside hardened test enclosures designed to contain these hazards. Some of the key response mechanisms that should be considered when designing such enclosures include applied blast loads for pneumatic testing), localized barrier perforation, global or gross barrier response, and generation of secondary debris from damage to a barrier, such as back-face spalling. Some of these hazards and shielding responses have been evaluated experimentally in the High Pressure Testing Safety Research Joint Industry Program [1, 2, 3]. This paper describes some of these hazards and some considerations for providing personnel protection.

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