osmole

オスモル

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Osm

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/07/23 01:06:23」(JST)

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This article is about the unit. For the concept, see Osmolarity.

In chemistry, the osmole (Osm or osmol) is a non-SI unit of measurement that defines the number of moles of solute that contribute to the osmotic pressure of a solution. The term comes from the phenomenon of osmosis, and is typically used for osmotically active solutions. For example, a solution of 1 mol/L NaCl corresponds to an osmolarity of 2 osmol/L. The NaCl salt particle dissociates fully in water to become two separate particles: an Na⁺ ion and a Cl^- ion. Therefore, each mole of NaCl becomes two osmoles in solution, one mole of Na⁺ and one mole of Cl^-. Similarly, a solution of 1 mol/L CaCl₂, gives a solution of 3 osmol/L (Ca²⁺ and 2 Cl^-).

The difference between osmolarity and molarity can be easily explained by an example. A physiological saline solution can be made by 9 g of sodium chloride dissolved in 1 liter of water, or 50 grams of glucose in 1 liter. Salt has a molar mass of 58.44 g/mol, glucose of 180.15 g/mol. 50 grams of glucose results in 278 millimoles of glucose. 9 g of sodium chloride correspond to 154 millimoles of sodium chloride. The osmolarity of the solution of sodium chloride, however, is 308 milliosmoles / liter. This difference is due to the number of particles after solvation: one molecule of sodium chloride in water splits into two ions. Glucose, however, remains one molecule after dissolvation. As a result, the osmolarity of 50 g of glucose in 1 liter of water is approximately equal to 9 g of sodium chloride in 1 liter of water.

A milliosmole (mOsm) is 1/1,000 of an osmole. A microosmole (μOsm) (also spelled micro-osmole) is 1/1,000,000 of an osmole.

References

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• 1. 血清浸透圧ギャップ serum osmolal gap
• 2. 成人における低ナトリウム血症の原因 causes of hyponatremia in adults
• 3. 透析不均衡症候群 dialysis disequilibrium syndrome
• 4. 急性腎障害（急性腎不全）における腎代替療法（透析）：代謝および血行動態に関する考慮事項 renal replacement therapy dialysis in acute kidney injury acute renal failure metabolic and hemodynamic considerations
• 5. 低ナトリウム血症を有する成人の評価 evaluation of adults with hyponatremia

English Journal

• Comparative accuracy of several published formulae for the estimation of serum osmolality in cats.

• Dugger DT, Mellema MS, Hopper K, Epstein SE.Author information William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, 1 Shields Avenue, Davis, CA 95616, USAAbstractOBJECTIVE: To determine the osmole gap utilizing 18 previously published formulae for the estimation of serum osmolality in cats.
• The Journal of small animal practice.J Small Anim Pract.2013 Apr;54(4):184-9. doi: 10.1111/jsap.12046.
• OBJECTIVE: To determine the osmole gap utilizing 18 previously published formulae for the estimation of serum osmolality in cats.PROCEDURES: Serum samples were frozen at -80°C after routine biochemical analysis. An Advanced Micro Osmometer 3300 was used to measure serum osmolality. Eighteen previou
• PMID 23496100

• New insights into urea and glucose handling by the kidney, and the urine concentrating mechanism.

• Bankir L, Yang B.Author information INSERM Unit 872/Equipe 2, Centre de Recherche des Cordeliers, Paris, France. lise.bankir@inserm.frAbstractThe mechanism by which urine is concentrated in the mammalian kidney remains incompletely understood. Urea is the dominant urinary osmole in most mammals and may be concentrated a 100-fold above its plasma level in humans and even more in rodents. Several facilitated urea transporters have been cloned. The phenotypes of mice with deletion of the transporters expressed in the kidney have challenged two previously well-accepted paradigms regarding urea and sodium handling in the renal medulla but have provided no alternative explanation for the accumulation of solutes that occurs in the inner medulla. In this review, we present evidence supporting the existence of an active urea secretion in the pars recta of the proximal tubule and explain how it changes our views regarding intrarenal urea handling and UT-A2 function. The transporter responsible for this secretion could be SGLT1, a sodium-glucose cotransporter that also transports urea. Glucagon may have a role in the regulation of this secretion. Further, we describe a possible transfer of osmotic energy from the outer to the inner medulla via an intrarenal Cori cycle converting glucose to lactate and back. Finally, we propose that an active urea transporter, expressed in the urothelium, may continuously reclaim urea that diffuses out of the ureter and bladder. These hypotheses are all based on published findings. They may not all be confirmed later on, but we hope they will stimulate further research in new directions.
• Kidney international.Kidney Int.2012 Jun;81(12):1179-98. doi: 10.1038/ki.2012.67. Epub 2012 Mar 28.
• The mechanism by which urine is concentrated in the mammalian kidney remains incompletely understood. Urea is the dominant urinary osmole in most mammals and may be concentrated a 100-fold above its plasma level in humans and even more in rodents. Several facilitated urea transporters have been clon
• PMID 22456603

• Localization of tubular adaptation to renal sodium loss in Gitelman syndrome.

• Favre GA, Nau V, Kolb I, Vargas-Poussou R, Hannedouche T, Moulin B.Author information Nephrology Department, Strasbourg University Hospital, France. favre@unice.frAbstractBACKGROUND AND OBJECTIVES: Gitelman syndrome (GS) is a salt-wasting tubulopathy that results from the inactivation of the human thiazide-sensitive sodium chloride cotransporter located in the distal convoluted tubule. Tubular adaptation to renal sodium loss has been described and localized in the distal tubule in experimental models of GS but not in humans with GS.
• Clinical journal of the American Society of Nephrology : CJASN.Clin J Am Soc Nephrol.2012 Mar;7(3):472-8. doi: 10.2215/CJN.00940111. Epub 2012 Jan 12.
• BACKGROUND AND OBJECTIVES: Gitelman syndrome (GS) is a salt-wasting tubulopathy that results from the inactivation of the human thiazide-sensitive sodium chloride cotransporter located in the distal convoluted tubule. Tubular adaptation to renal sodium loss has been described and localized in the di
• PMID 22241817

Related Links

• Osmole (unit) - Wikipedia, the free encyclopedia

A strict definition of an osmole is the number of osmotically active particles that, when dissolved in 22.4 L of solvent at 0 degrees Celsius, exert an osmotic pressure of 1 atmosphere. This is equivalent to the observation that 1 mole of a perfect ...

• osmole - definition of osmole in the Medical dictionary - by the Free ...

osmole /os·mole/ (oz´mol) a unit of osmotic pressure equivalent to the amount of solute that dissociates in solution to form one mole (Avogadro's number) of particles (molecules and ions). Symbol Osm.

Related Pictures

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★リンクテーブル★

リンク元	「オスモル」
拡張検索	「milliosmole」

「オスモル」

　　[★]

英

osmole

同

Osm

関

浸透圧

• 一定量の液体に含まれる粒子の数。
• 浸透圧を表現するために用いられる。
• 書籍などでOsmと表記されている場合には重量もしくは体積の次元が省略されていると考えてよい？たとえばOsm→Osm/kg、Osm/l。

0.9% NaCl = 154 mEq Na⁺/L + 154 mEq Cl^-/L

= 154 mOsm Na⁺/L + 154 mOsm Cl^-/L

= 308 mOsm

「milliosmole」

　　[★]

ミリオスモル

関

mOsm、mosmol