Disease relevance of Osmolar Concentration

• We found that a water load suppressed plasma osmolality and vasopressin and urine osmolality in both groups, but that urinary dilution and free water clearance were impaired in the patients with hyponatremia, even though plasma levels of vasopressin and solute clearance were similar in the two groups [1].
• Monitoring serum osmolality in mannitol treatment of Reye's syndrome [2].
• We suggest that VP1, the major capsid protein, can act as a nucleosome unfolding agent in neutral pH and low ionic strength [3].
• We postulate that the increase in GFR which emerges as a consequence of increased plasma osmolality in diabetes mellitus delivers more albumin to the proximal tubule than can be reabsorbed [4].
• Sustained effect of glucose-insulin-potassium on myocardial performance during regional ischemia. Role of free fatty acid and osmolality [5].

Psychiatry related information on Osmolar Concentration

• She had little increase in urine osmolality in response to water deprivation, hypertonic-saline infusion, and vasopressin injection and no response to desmopressin acetate (1-deamino-8-D-arginine vasopressin) during the immediate postpartum period [6].
• The effects of hydrogel composition, ionic strength, temperature, and factors influencing reversibility and response time are evaluated [7].
• In a separate group of rats, drinking behavior was stimulated by increases in plasma osmolality, and mean AP was raised by an infusion of phenylephrine (PE) [8].
• In the first subject, with polycystic ovarian disease, posterior pituitary peptide levels were in the normal range, whereas the other subject, recovering from anorexia nervosa, had raised plasma levels of all posterior pituitary peptides (AVP 8.1 pmol/l, OT 1.8 pmol/l, NPOT 131 pmol/l, mean values) despite a normal osmolality [9].
• RESULTS: Conventional lactate-buffered solutions are known to inhibit or modulate cell functions related to host defense mechanisms; these effects are mediated by their low pH in combination with lactate concentration, as well as their glucose content, associated osmolality, and the presence of glucose breakdown products [10].

High impact information on Osmolar Concentration

• In Saccharomyces cerevisiae, there are five MAPK pathways involved in mating, cell wall remodelling, nutrient deprivation, and responses to stress stimuli such as osmolarity changes [11].
• When four of the patients were later restudied while receiving maintenance hydrocortisone treatment, the relation between plasma vasopressin and osmolality was normal [12].
• Furthermore, topA mutations can mimic an increase in osmolarity, facilitating proU expression even in media of low osmolarity in which it is not normally expressed [13].
• An increase in extracellular osmolarity increases in vivo DNA supercoiling, and the expression of proU is highly sensitive to these changes [13].
• These structures form below 40 degrees C at moderate ionic strength and neutral pH and behave like hairpin duplexes in nondenaturing polyacrylamide gels [14].

Chemical compound and disease context of Osmolar Concentration

• Urinary osmolality after water deprivation for 24 h and administration of antidiuretic hormone was 2,501+/-217 and 2,874+/-392 mosmol/kg H2O in intact and uninephrectomized control rats, respectively, and 929+/-130 mosmol/kg H2O in pyelonephritic rats (P less than 0.001 compared to each control group) [15].
• During the fourth to seventh week after the start of the experiment, malignant hypertension developed in most of the animals: body weight fell, reflecting volume depletion; serum osmolality and serum sodium and urea concentrations increased; in the kidneys malignant nephrosclerosis occurred [16].
• Ten of the thirteen patients in shock had raised angiotensin-II concentrations in peripheral blood and acute renal failure manifested by oliguria, increasing serum-creatinine, a urine osmolality of less than 400 mos-mol/kg and a urine/plasma osmolality ratio of less than 1-5 [17].
• The superstructure of a covalently closed circular DNA (of bacteriophage PM 2) was compared by electron microscopy with that of a linear duplex DNA (of bacteriophage T7) when ionic strength and benzyldimethylalkylammonium chloride concentration were varied [18].
• Erythrocyte ghosts prepared by osmotic hemolysis and resealed by treatment with Mg2+ or elevated ionic strength exhibit a difference in fluidity between phosphatidylcholine and phosphatidylethanolamine spin labels, although less than that observed in whole cells [19].

Biological context of Osmolar Concentration

• Arginine-vasopressin (AVP) is a neurohypophysial nonapeptide with antidiuretic activity involved in the control of blood volume and plasma osmolality [20].
• At 4 h, 0.75 and 1.0 mg/kg of OPC-31260 almost doubled the plasma arginine vasopressin; and the higher doses increased plasma osmolality and plasma Na slightly, but did not alter plasma K, blood pressure, or heart rate [21].
• Urea, infused in a solution whose osmolality and volume were identical to the imidazole infusion, failed to improve hemodynamics in the POK, making it unlikely that nonspecific effects of volume expansion or osmotic diuresis mediated the beneficial effect of imidazole [22].
• Raffinose or choline chloride substitution showed that osmolality, rather than NaCl, signalled cell volume maintenance in hyperosmotic media [23].
• We have found that dephosphorylated synapsin I induces a dose-dependent increase in the number of actin filaments, which at high ionic strength is abolished by synapsin I phosphorylation [24].

Anatomical context of Osmolar Concentration

• In three patients given lithium carbonate (900 mg daily) the serum sodium concentration, urine osmolality and urine volume were unchanged; since two patients had adverse central-nervous-system symptoms during lithium therapy, further study of this agent was abandoned [25].
• At physiological ionic strength and pH, nonphosphorylated smooth muscle and non-muscle myosin filaments are disassembled by stoichiometric levels of MgATP, forming species having sedimentation coefficients of approximately 11S (range 10-12S; myosin monomers in high salt sediment at 6S) [26].
• Many environmental stresses (such as shifts in temperature or osmolarity) provoke transient depolarization of the actin cytoskeleton, during which bud construction is delayed while cells adapt to environmental conditions [27].
• Calcium uptake into human intestinal brush border membrane vesicles represented uptake into intravesicular space as evidenced by studies of osmolality, temperature dependence, calcium ionophore A23187-induced efflux and influx, and lanthanum displacement [28].
• On day 3, mannitol solutions of increasing osmolality 370, 520, and 700 mosmol X kg-1 were infused into the duodenum at 0.2 ml X min-1 [29].

Associations of Osmolar Concentration with chemical compounds

• A simple and direct way to assess whether tonicity is normal is to calculate the effective osmolality from the concentrations of sodium and glucose in serum [30].
• Moreover, during water loading and infusion of hypertonic saline, the plasma level of vasopressin was higher at any given plasma osmolality in the test patients than in the controls, indicating a downward resetting of the osmostat [1].
• At that time, the urinary sodium level and the osmolality averaged 68 mmol per liter and 501 mOsm per kilogram, suggesting inappropriate secretion of antidiuretic hormone [31].
• What fraction of total RNA synthesized is 5S RNA is strongly affected by DNA concentration, ionic strength and MgCl2 concentration [32].
• The tyrosine kinase Pyk2 was activated by tumor necrosis factor alpha, by ultraviolet irradiation, and by changes in osmolarity [33].

Gene context of Osmolar Concentration

• Both HOG1 and p38 are tyrosine phosphorylated after extracellular changes in osmolarity [34].
• Mutants that were not able to activate PBS2 MAP kinase kinase (MAPKK; Pbs2p) at high osmolarity were characterized [35].
• The MAPKKK Ste11p functions in three Saccharomyces cerevisiae MAPK cascades [the high osmolarity glycerol (HOG), pheromone response, and pseudohyphal/invasive growth pathways], but its activation in response to high osmolarity stimulates only the HOG pathway [36].
• V2R-deficient hemizygous male pups showed a decrease in basal urine osmolalities and were unable to concentrate their urine [37].
• These results are also discussed with regard to the mechanism underlying regulation of the proV promoter in response to the medium osmolarity [38].

Analytical, diagnostic and therapeutic context of Osmolar Concentration

• Furosemide significantly decreased urine osmolality and urea clearance, and increased blood urea nitrogen [39].
• Hemodialysis with non-urea bath decreased plasma urea by 21 mM, and plasma osmolality by 22 mosmol/kg H2O, and increased brain water content by 8.0% (all < 0.05), while hemodialysis with urea bath did not affect plasma urea, osmolality, or brain water content [40].
• Selective response of human airway epithelia to luminal but not serosal solution hypertonicity. Possible role for proximal airway epithelia as an osmolality transducer [41].
• Assuming that luminal fluid reaches osmotic equilibrium with plasma during total gut perfusion, this result suggests that the vapor pressure osmometer accurately reflects the biologically relevant osmolality of intestinal contents [42].
• Genetic and microarray analysis indicates that high osmolarity extends the life span by activating Hog1p, leading to an increase in the biosynthesis of glycerol from glycolytic intermediates [43].

References