Seizure and acute osmotic change: Clinical and neurophysiological aspects

1991 ◽  
Vol 101 (1) ◽  
pp. 7-18 ◽  
Author(s):  
R.David Andrew
Keyword(s):  
Osmotic Change

scholarly journals Proximal tubule volume regulation in hypo-osmotic media: intracellular K+, Na+, and Cl-.

1990 ◽  
Vol 1 (2) ◽  
pp. 211-218
Author(s):  
L Rome ◽  
C Lechene ◽  
J J Grantham
Keyword(s):  
Cell Volume ◽  
Volume Regulation ◽  
Cell Volume Regulation ◽  
Rabbit Kidney ◽  
Kidney Cortex ◽  
Volume Regulatory Decrease ◽  
Osmotic Change ◽  
Electrolyte Loss ◽  
The Difference

This study sought to measure the net loss of intracellular K+, Na+, and Cl- that accompanied isosmotic cell volume regulation in hypotonic media and to determine if electrolyte loss depended on the rate at which the extracellular osmolality was reduced. Isolated nonperfused proximal S2 segments from rabbit kidney cortex were studied in vitro. Gradual lowering of osmolality from 295 to 150 mOsm/kg at a rate of 2 mOsm/kg/min did not cause an increase in tubule cell volume until the medium osmolality decreased below 190 mOsm/kg. By contrast, tubules rapidly bathed in low osmolality media exhibited classical osmometric swelling followed by incomplete volume regulatory decrease. Volume regulation associated with gradual and rapid lowering of osmolality was accompanied by the net loss of intracellular K+, Na+, and Cl- (measured by electron probe); however, the temporal pattern of electrolyte loss depended on the rate of osmotic change. With gradual lowering of osmolality, cell K+ content did not decrease significantly until osmolality was lowered below 200 mOsm/kg, whereas Cl- was lost at the 200 mOsm/kg level and below. With rapid lowering of osmolality, cell K+ content was strikingly decreased at the 200 mOsm/kg level, but Cl- did not change appreciably until osmolality was decreased to 150 mOsm/kg. Cell Na+ content decreased in hypo-osmotic media, but the magnitude was relatively small. During volume regulation that accompanied either gradual or rapid lowering of medium osmolality from 295 to 150 mOsm/kg, intracellular osmolal gap, the difference between medium osmolality and the sum of intracellular concentrations of K+, Na+, and Cl- decreased 87 and 58 mOsm/kg, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Initiation of sperm motility in the newt, Cynops pyrrhogaster, is induced by a heat-stable component of egg-jelly

Zygote ◽  
1999 ◽  
Vol 7 (4) ◽  
pp. 329-334 ◽  
Author(s):  
Jun-Ichi Mizuno ◽  
Akihiko Watanabe ◽  
Kazuo Onitake
Keyword(s):  
Heat Treatment ◽  
Sperm Motility ◽  
Regulatory Mechanism ◽  
Cynops Pyrrhogaster ◽  
Stable Component ◽  
Heat Stable ◽  
Heat Treated ◽  
Osmotic Change ◽  
Inactive Form ◽  
Before And After

Sperm motility in amphibians is thought to be initiated by a decrease in environmental osmolarity. However, fertilisation in the newt, Cynops pyrrhogaster, is achieved in an environment without osmotic change. We show here that sperm motility initiating activity is present in jelly layer extract (JE). JE was gel-filtrated and a single peak with sperm motility initiating activity was detected in the fraction corresponding to about 50 kDa. The activity was strengthened by heat treatment of JE at 100 °C for 30 min. This suggests that JE includes the inactive form of sperm motility inducing substance (SMIS) in addition to active substance. Thus JE was fractionated before and after the heat treatment. When JE was fractionated first and then each fraction was heated, the activity was detected in the fraction both above 500 kDa and below 500 kDa. When heat-treated JE was fractionated, the activity was detected only in the fraction below 500 kDa. These results suggest that JE includes the inactive form of SMIS of more than 500 kDa in molecular weight. A regulatory mechanism for the initiation of sperm motility in C. pyrrhogaster is proposed according to the results of the present study.

Effects of plasma volume and osmolality on secretion of atrial natriuretic peptide and vasopressin in man

1988 ◽  
Vol 118 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Kyuzi Kamoi ◽  
Fujio Sato ◽  
Okuhiro Arai ◽  
Miyuki Ishibashi ◽  
Tohru Yamaji
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Plasma Volume ◽  
Plasma Osmolality ◽  
Plasma Sodium ◽  
Water Load ◽  
Healthy Men ◽  
Parallel Increase ◽  
Osmotic Change ◽  
Atrial Natriuretic

Abstract. To clarify the role of blood volume and osmolality in the mediation of the release of atrial natriuretic peptide (ANP) and to examine the relationship between plasma ANP and plasma AVP levels in man, the effects of hypertonic saline and hypertonic mannitol infusion, and of water load on plasma levels of ANP and AVP were studied. Infusion of 5% saline to 7 healthy men at a rate of 0.05 ml min−1·kg−1 for 2 h resulted in a parallel rise in plasma sodium, osmolality, plasma ANP and plasma AVP, indicating that plasma hyperosmolality stimulates secretion of both ANP and AVP. Infusion of 20% mannitol to 6 healthy men at the same rate resulted in a parallel increase in plasma osmolality, plasma ANP and AVP, whereas plasma sodium decreased, indicating that plasma hyperosmolality stimulates secretion of both ANP and AVP. Water load (20 ml/kg) into 7 healthy men produced a prompt and parallel fall in plasma sodium, plasma osmolality and plasma AVP. In contrast, plasma ANP and plasma volume, calculated from the changes in hematocrit, increased concomitantly, which indicates that expanded plasma volume stimulates secretion of plasma ANP. These results suggest that secretion of ANP in man is regulated principally by plasma volume, which may be modulated by a change in plasma osmolality. AVP secretion, on the other hand, is controlled mainly by osmotic change and secondarily by plasma volume.

scholarly journals Evaluation of an Acute Osmotic Stress in European Sea Bass via Skin Mucus Biomarkers

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1546
Author(s):  
Borja Ordóñez-Grande ◽  
Pedro M. Guerreiro ◽  
Ignasi Sanahuja ◽  
Laura Fernández-Alacid ◽  
Antoni Ibarz
Keyword(s):  
Environmental Changes ◽  
Acute Stress ◽  
Sampling Technique ◽  
Sea Bass ◽  
European Sea Bass ◽  
Skin Mucus ◽  
Osmotic Change ◽  
Extreme Salinity ◽  
Hyperosmotic Condition ◽  
Acute Stress Response

European sea bass is a marine teleost which can inhabit a broad range of environmental salinities. So far, no research has studied the physiological response of this fish to salinity challenges using modifications in skin mucus as a potential biological matrix. Here, we used a skin mucus sampling technique to evaluate the response of sea bass to several acute osmotic challenges (for 3 h) from seawater (35‰) to two hypoosmotic environments, diluted brackish water (3‰) and estuarine waters (12‰), and to one hyperosmotic condition (50‰). For this, we recorded the volume of mucus exuded and compared the main stress-related biomarkers and osmosis-related parameters in skin mucus and plasma. Sea bass exuded the greatest volume of skin mucus with the highest total contents of cortisol, glucose, and protein under hypersalinity. This indicates an exacerbated acute stress response with possible energy losses if the condition is sustained over time. Under hyposalinity, the response depended on the magnitude of the osmotic change: shifting to 3‰ was an extreme salinity change, which affected fish aerobic metabolism by acutely modifying lactate exudation. All these data enhance the current scarce knowledge of skin mucus as a target through which to study environmental changes and fish status.

scholarly journals The Rate of Osmotic Downshock Determines the Survival Probability of Bacterial Mechanosensitive Channel Mutants

2014 ◽  
Vol 197 (1) ◽  
pp. 231-237 ◽  
Author(s):  
Maja Bialecka-Fornal ◽  
Heun Jin Lee ◽  
Rob Phillips
Keyword(s):  
Environmental Changes ◽  
Cultured Cells ◽  
Osmotic Shock ◽  
Survival Rates ◽  
Content Type ◽  
Prevailing Paradigm ◽  
Osmotic Change ◽  
Limited Effectiveness ◽  
Sense And Respond ◽  
Changes Over Time

Mechanosensitive (MS) channels allow cells to sense and respond to environmental changes. In bacteria, these channels are believed to protect against an osmotic shock. The physiological function of these channels has been characterized primarily by a standardized assay, where aliquots of batch-cultured cells are rapidly pipetted into a hypotonic medium. Under this method, it has been inferred many types of MS channels (MscS homologs inEscherichia coli) demonstrate limited effectiveness against shock, typically rescuing less than 10% of the cells when expressed at native levels. We introduce a single-cell-based assay which allows us to control how fast the osmolarity changes, over time scales ranging from a fraction of a second to several minutes. We find that the protection provided by MS channels depends strongly on the rate of osmotic change, revealing that, under a slow enough osmotic drop, MscS homologs can lead to survival rates comparable to those found in wild-type strains. Further, after the osmotic downshift, we observe multiple death phenotypes, which are inconsistent with the prevailing paradigm of how cells lyse. Both of these findings require a reevaluation of our basic understanding of the physiology of MS channels.

scholarly journals Resuscitation of soil microbiota after > 70-years of desiccation

2020 ◽  
Author(s):  
Jun Zhao ◽  
Dongfeng Chen ◽  
Wei Gao ◽  
Zhiying Guo ◽  
Zhongjun Jia ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Bacterial Abundance ◽  
Storage Conditions ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Sequencing Analysis ◽  
Osmotic Change ◽  
Abundance And Diversity ◽  
Strong Adaptation

AbstractThe abundance and diversity of bacteria in 24 historical soil samples under air-dried storage conditions for more than 70 years were assessed by quantification and high-throughput sequencing analysis of 16S rRNA genes. All soils contained a measurable abundance of bacteria varying from 103 to 108 per gram of soil and contrasting community compositions were observed in different background soils, suggesting that the bacteria detected were indigenous to the soil. Following a 4-week soil rewetting event, the bacterial abundance significantly increased in soils, indicating strong adaptation of soil bacteria to extreme osmotic change and high resuscitation potential of some bacteria over long periods of desiccation. Paenibacillus, Cohnella and two unclassified Bacillales genera within the phylum Firmicutes represented the most ubiquitously active taxa, which showed growth in the highest number of soils (≥12 soils), while genera Tumebacillus, Alicyclobacillus and Brevibacillus in the phylum Firmicutes displayed the highest growth rates in soils (with >1000-fold average increase) following rewetting. Additionally, some Actinobacteria and Proteobacteria genera showed relatively high activity following rewetting, suggesting that the resilience to long-term desiccation and rewetting is a common trait across phylogenetically divergent microbes. The present study thus demonstrated that diversified groups of microbes are present and potentially active in historically desiccated soils, which might be of importance in the context of microbial ecology.

scholarly journals Solute Transport Controls Membrane Tension and Organellar Volume

2021 ◽  
Vol 55 (S1) ◽  
pp. 1-24
Keyword(s):  
Solute Transport ◽  
Endocytic Pathway ◽  
Coat Proteins ◽  
Lysosomal Storage ◽  
Transport Pathways ◽  
Osmotic Change ◽  
Solute Fluxes ◽  
Organic Solute ◽  
Membrane Bound ◽  
Sense And Respond

The regulation of cellular volume in response to osmotic change has largely been studied at the whole cell level. Such regulation occurs by the inhibition or activation of ionic and organic solute transport pathways at the cell surface and is coincident with remodelling of the plasma membrane. However, it is only in rare instances that osmotic insults are experienced by cells and tissues. By contrast, the relatively minute luminal volumes of membrane-bound organelles are constantly subject to shifts in their solute concentrations as exemplified in the endocytic pathway where these evolve alongside with maturation. In this review, we summarize recent evidence that suggests trafficking events are in fact orchestrated by the solute fluxes of organelles that briefly impose osmotic gradients. We first describe how hydrostatic pressure and the resultant tension on endomembranes can be readily dissipated by controlled solute efflux since water is obliged to exit. In such cases, the relief of tension on the limiting membrane of the organelle can promote its remodelling by coat proteins, ESCRT machinery, and motors. Second, and reciprocally, we propose that osmotic gradients between organellar lumens and the cytosol may persist or be created. Such gradients impose osmotic pressure and tension on the endomembrane that prevent its remodelling. The control of endomembrane tension is dysregulated in lysosomal storage disorders and can be usurped by pathogens in endolysosomes. Since trafficking and signaling pathways conceivably sense and respond to endomembrane tension, we anticipate that understanding how cells control organellar volumes and the movement of endocytic fluid in particular will be an exciting new area of research.

Brain and CSF water and ions in newborn puppies during acute hypo- and hypernatremia

1981 ◽  
Vol 51 (5) ◽  
pp. 1086-1091 ◽  
Author(s):  
E. E. Nattie ◽  
W. H. Edwards
Keyword(s):  
Cerebrospinal Fluid ◽  
Volume Regulation ◽  
Extracellular Volume ◽  
Chloride Content ◽  
Brain Cell ◽  
Acid Base ◽  
Osmotic Change ◽  
Acute Hyponatremia ◽  
The Brain ◽  
Brain Water

We studied the fluid and electrolyte response of the brain and cerebrospinal fluid (CSF) in the lightly anesthetized newborn puppy exposed to acute (1–3 h) mild hyponatremia (12% decrease) and hypernatremia (7% increase). The changes in CSF osmolality, sodium, and chloride were equal to those in plasma. Blood acid-base values and CSF PCO2 remained normal, but in CSF there was a transient dilution acidosis in hyponatremia and contraction alkalosis in hypernatremia. In brain tissue, with hyponatremia, brain water increased in proportion to the osmotic stress (a change which was greater than that previously observed in adults) and the chloride space increased in the puppy (a change that was opposite to that observed in adults). There were no significant changes in dry tissue potassium, sodium, or chloride content. In hypernatremia, brain water decreased less than predicted by the osmotic change, the chloride space was unchanged, dry tissue potassium and chloride increased, and sodium was unchanged. In the newborn puppy, brain cell and extracellular volume regulation is not apparent with acute hyponatremia but is with hypernatremia.

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