Evans blue (dye): Difference between revisions

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 417240354

| ImageFile = Evans Blue.svg

| ImageSize = 310px

| ImageFile1 = Evans blue sodium 3D spacefill.png

| ImageSize1 = 310

| ImageAlt1 = Space-filling model of the Evans blue molecule, sodium salt

| Name = Evans blue

|Section1={{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|??}}

| CASNo = 314-13-6

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 45PG892GO1

| ChEMBL_Ref = {{ebicite|changed|EBI}}

| ChEMBL = 1200712

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 82467

| PubChem = 6321418

| SMILES = [Na+].[Na+].[Na+].[Na+].[O-]S(=O)(=O)c6cc(c(N)c5c6C=C/C(=N\Nc1ccc(cc1C)c4ccc(N\N=C3/C=Cc2c(cc(c(N)c2C3=O)S([O-])(=O)=O)S([O-])(=O)=O)c(C)c4)C5=O)S([O-])(=O)=O

| MeSHName = Evans+blue

| KEGG_Ref = {{keggcite|changed|kegg}}

| KEGG = C19422

|Section2={{Chembox Properties

| C=34 | H=24 | N=6 | Na=4 | O=14 | S=4

| MolarMass = 960.809

| Appearance =

| Density =

| MeltingPt =

| BoilingPt =

|Section3={{Chembox Hazards

| MainHazards =

| FlashPt =

| AutoignitionPt =

'''T-1824''' or '''Evans blue''', often incorrectly rendered as '''Evan's blue''', is an [[azo dye]] that has a very high affinity for [[serum albumin]]. Because of this, it can be useful in [[physiology]] in estimating the proportion of [[body water]] contained in [[blood plasma]].<ref>{{cite book| title= Essentials of Human Physiology| first= Thomas M. |last= Nosek| chapter=Section 7/7ch02/7ch02p17 |chapter-url=http://humanphysiology.tuars.com/program/section7/7ch02/7ch02p17.htm |archive-url=https://web.archive.org/web/20160324124828/http://humanphysiology.tuars.com/program/section7/7ch02/7ch02p17.htm|archive-date=2016-03-24}}</ref> It fluoresces with excitation peaks at 470 and 540&nbsp;nm and an emission peak at 680&nbsp;nm.<ref>{{cite journal|year=1983|title=A Simple Fluorescence Technique to Stain the Plasma Membrane of Human Neutrophils|journal=Histochemistry|volume=79|issue=1|pages=105–10|doi=10.1007/BF00494347|pmid=6196326|vauthors=Hed J, Dahlgren C, Rundquist I|s2cid=785829 }}</ref>

Evans blue dye has been used as a [[viability assay]] on the basis of its penetration into non-viable cells, although the method is subject to error because it assumes that damaged or otherwise altered cells are not capable of repair and therefore are not viable.<ref>{{cite journal | vauthors=Crutchfield A, Diller K, Brand J | title=Cryopreservation of Chlamydomonas reinhardtii (Chlorophyta) | journal= [[European Journal of Phycology]] | volume=34 | issue=1 | year=1999 | pages=43–52 | doi = 10.1080/09670269910001736072 }}</ref>

Evans blue is also used to assess the permeability of the [[blood–brain barrier]] to macromolecules. Because serum albumin cannot cross the barrier and virtually all Evans blue is bound to albumin, normally the neural tissue remains unstained.<ref>{{cite journal| title=Fluorescence imaging of blood–brain barrier disruption | vauthors=Hawkins BT, Egleton RD | journal=Journal of Neuroscience Methods| volume=151 | issue=2 | pages=262–7 | year=2006| doi=10.1016/j.jneumeth.2005.08.006| pmid=16181683| s2cid=31154215 }}</ref> When the blood–brain barrier has been compromised, albumin-bound Evans blue enters the CNS.

Evans blue is pharmacologically active, acting as a [[negative allosteric modulator]] of the [[AMPA receptor|AMPA]] and [[kainate receptor]]s and as an [[reuptake inhibitor|inhibitor]] of [[Excitatory amino-acid transporter#VGLUTs|vesicular glutamate transporter]]s.<ref>{{Cite journal|last1=Schürmann|first1=B.|last2=Wu|first2=X.|last3=Dietzel|first3=I. D.|last4=Lessmann|first4=V.|date=May 1997|title=Differential modulation of AMPA receptor mediated currents by evans blue in postnatal rat hippocampal neurones|journal=British Journal of Pharmacology|volume=121|issue=2|pages=237–247|doi=10.1038/sj.bjp.0701125|issn=0007-1188|pmc=1564681|pmid=9154333}}</ref><ref>{{Cite journal|last1=Price|first1=C. J.|last2=Raymond|first2=L. A.|date=December 1996|title=Evans blue antagonizes both alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate and kainate receptors and modulates receptor desensitization|journal=Molecular Pharmacology|volume=50|issue=6|pages=1665–1671|issn=0026-895X|pmid=8967991}}</ref> It also acts on [[P2 receptor]]s.<ref>{{Cite journal|last1=Wittenburg|first1=H.|last2=Bültmann|first2=R.|last3=Pause|first3=B.|last4=Ganter|first4=C.|last5=Kurz|first5=G.|last6=Starke|first6=K.|date=October 1996|title=P2-purinoceptor antagonists: II. Blockade of P2-purinoceptor subtypes and ecto-nucleotidases by compounds related to Evans blue and trypan blue|journal=Naunyn-Schmiedeberg's Archives of Pharmacology|volume=354|issue=4|pages=491–497|doi=10.1007/bf00168441|issn=0028-1298|pmid=8897453|s2cid=22823820 }}</ref>

It was named after [[Herbert McLean Evans]], an American anatomist.<ref>{{Cite journal|last=Venes|first=Donald|title=Evans Blue|journal=[[Taber's Cyclopedic Medical Dictionary]]|volume=21|pages=818}}</ref>

{{Reflist}}

<references responsive="0" />

* {{cite journal |vauthors=el-Sayed H, Goodall S, Hainsworth R |title=Re-evaluation of Evans blue dye dilution method of plasma volume measurement |journal=Clin Lab Haematol |volume=17 |issue=2 |pages=189–94 |year=1995 |pmid=8536425}}

{{GABA metabolism and transport modulators}}

{{Ionotropic glutamate receptor modulators}}

{{Glutamate metabolism and transport modulators}}

{{Purine receptor modulators}}

[[Category:AMPA receptor antagonists]]

[[Category:Kainate receptor antagonists]]

[[Category:Naphthylamines]]

[[Category:Negative allosteric modulators]]