Evans blue

February 10, 2024
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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. It fluoresces with excitation peaks at 470 and 540 nm and an emission peak at 680 nm.

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.

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. 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 and kainate receptors and as an inhibitor of vesicular glutamate transporters. It also acts on P2 receptors.

It was named after Herbert McLean Evans, an American anatomist.

Portrait of Herbert M. Evans in laboratory, with signed inscription to J. C. Drummond, 11 January 1927. Drummond may be Jack Cecil Spinks (Drummond), a biochemist, noted for his work on nutrition as applied to the British diet under rationing during the Second World War. Later, a victim in what became known as the Dominici affair. https://en.wikipedia.org/wiki/Jack_Drummond

Herbert McLean Evans (September 23, 1882 – March 6, 1971) was an American anatomist and embryologist best known for co-discovering Vitamin E. He was born in Modesto, California. In 1908, he obtained his medical degree from Johns Hopkins University. Evans became associate professor of anatomy at Johns Hopkins University. Evans moved back to California in 1915 and was made professor of anatomy at the University of California, Berkeley, and held that position until his death in Berkeley, California, aged 88. Evans took a strong interest in the history of science and was an active collector of rare books in the field. His collection was later acquired by the Harry Ransom Center at the University of Texas at Austin.

Trained as an anatomist, Katharine J. Scott Bishop (1889-1976) graduated from Johns Hopkins University School of Medicine in 1915 and, working with Herbert M. Evans, discovered the importance of Vitamin E.

His medical research at Berkeley addressed problems relating to human nutrition, endocrinology, embryology, and histology. In 1918, his research into the number of human chromosomes led him to believe the number to be 48, when most people assumed the number to be much higher. Maybe his assistant had 48? It was only later discovered that the correct figure was 46. Evans had much greater success however with hormones extracted from the anterior lobe of the pituitary gland. He isolated Human Growth Hormone, which is essential for human growth and development. In 1922 along with Katharine Scott Bishop, during feeding experiments on rats, he co-discovered Vitamin E which is needed for human reproduction. Evans became director of the Institute of Experimental Biology at Berkeley in 1931. With Gladys Anderson Emerson, he reported the isolation of the pure Vitamin E from wheat germ in 1937. He also determined the formula C29H50O2.  Bishop’s page says:

When the rats were fed with a diet where lard was the only source of fat, though grew healthily, the female rats were unable to carry babies full term due to the breakdown of the placentas, and the male rats became sterile since the sperm-forming cells in the testes would deteriorate. Initially called “Factor X”, Bishop and Evans narrowed down that this factor came from the lipid extract of lettuce and wheat germ.

 Amoroso, Emmanuel Ciprian; Corner, George Washington (November 1972). “Herbert McLean Evans, 1882-1971”. Biographical Memoirs of Fellows of the Royal Society. 18: 82–186. doi:10.1098/rsbm.1972.0005. ISSN 0080-4606. PMID 11615755. S2CID 197608 and  “Katharine J. Scott Bishop – Biography – A History of UCSF”. history.library.ucsf.edu. Retrieved 2015-02-03.

That rings false to me.

Evans was also instrumental in developing reproductive systems research with Miriam Elizabeth Simpson and Choh Hao Li, by studying the oestrus cycle of rats.

Evans is also credited with developing Evans blue, a method which determines blood volume in humans and animals.

Quotation

  • “No single feature of man’s past equals in importance his attempt to understand the forces of Nature and himself.”

Bibliography

  • Evans, H. McLean (1904) A New Cestraciont Spine from the Lower Triassic of Idaho. The University Press: Berkeley, California.
  • Evans, H. McLean and Scott, Katharine J. (1921) On the Differential Reaction to Vital Dyes Exhibited by the Two Groups of Connective-tissue Cells. Carnegie Institution of Washington.
  • Evans, H. McLean and Long, Joseph A. (1922) The oestrous cycle in the rat and its associated phenomena. Univ. of California Press: Berkeley, California.
  • Evans, H. McLean and Cole, Harold H. (1931) An Introduction to the Study of the Oestrous Cycle in the Dog. University of California Press: Berkeley, California.
  • Evans, H. McLean and Swezy, Olive (1931) Ovogenesis and the Normal Follicular Cycle in Adult Mammalia. University of California Press: Berkeley, California.
  • Evans, H. McLean and Becks, Hermann (1953) Atlas of the Skeletal Development of the Rat (Long-Evans strain): normal and hypophysectomized. American Institute of Dental Medicine: San Francisco.
  • Evans, H. McLean, ed. (1959) Men and Moments in the History of Science. University of Washington Press: Seattle. ISBN 0-8371-2458-1

References

  1. Amoroso, E. C.; Corner, G. W. (1972). “Herbert McLean Evans 1882-1971”. Biographical Memoirs of Fellows of the Royal Society. 18: 82–186. doi:10.1098/rsbm.1972.0005. PMID 11615755. S2CID 197608.
  2. Mohammad, A.; Emerson, O. H.; Emerson, G. A.; Evans, H. M. (1939). “Multiple Nature of the Rat “filtrate Factor”–A Component of Vitamin B2″. Science. 90 (2338): 377. Bibcode:1939Sci….90..377M. doi:10.1126/science.90.2338.377. PMID 17754630.
  3. Emerson, O. H.; Emerson, G. A.; Evans, H. M. (1939). “The Occurrence of Gamma Tocopherol in Corn Embryo Oil”. Science. 89 (2304): 183. Bibcode:1939Sci….89..183E. doi:10.1126/science.89.2304.183. PMID 17834212.
  4. Evans, H. M.; Emerson, G. A.; Emerson, O. H. (1938). “The Chemistry of Vitamin E. Ii. Biological Assays of Various Synthetic Compounds”. Science. 88 (2271): 38–39. Bibcode:1938Sci….88…38E. doi:10.1126/science.88.2271.38. PMID 17780891.
  5. Emerson, O. H.; Emerson, G. A.; Evans, H. M. (1936). “The Isolation from Cottonseed Oil of an Alcohol Resembling Alpha Tocopherol from Wheat Germ Oil”. Science. 83 (2157): 421. Bibcode:1936Sci….83..421E. doi:10.1126/science.83.2157.421. PMID 17740452.
  6. Evans, H. M.; Bishop, K. S. (1922). “On the Existence of a Hitherto Unrecognized Dietary Factor Essential for Reproduction”. Science. 56 (1458): 650–651. Bibcode:1922Sci….56..650E. doi:10.1126/science.56.1458.650. PMID 17838496.
  7. Bowden, Mary Ellen; Crow, Amy Beth; Sullivan, Tracy (2003). Pharmaceutical achievers : the human face of pharmaceutical research. Philadelphia, PA: Chemical Heritage Press. pp. 35–37. ISBN 978-0941901307. Retrieved 27 October 2015.
  8. Elizabeth H. Oakes (2007), “Emerson, Gladys Anderson”, Encyclopedia of World Scientists, Infobase, pp. 211–212, ISBN 978-1438118826
  9. Evans H. M.; Emerson O. H.; Emerson G. A. (February 1, 1936). “The isolation from wheat germ oil of an alcohol, a-tocopherol, having the properties of vitamin E”. Journal of Biological Chemistry. 113 (1): 319–332. doi:10.1016/S0021-9258(18)74918-1.
  10. Evans, H. M.; Emerson, O. H.; Emerson, G. A. (2009). “THE ISOLATION FROM WHEAT GERM OIL OF AN ALCOHOL, α-TOCOPHEROL, HAVING THE PROPERTIES OF VITAMIN E”. Nutrition Reviews. 32 (3): 80–82. doi:10.1111/j.1753-4887.1974.tb06280.x. PMID 4593257.

External links

Fellows of the Royal Society elected in 1951

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References

  1. Nosek, Thomas M. “Section 7/7ch02/7ch02p17”. Essentials of Human Physiology. Archived from the original on 2016-03-24.
  2. Hed J, Dahlgren C, Rundquist I (1983). “A Simple Fluorescence Technique to Stain the Plasma Membrane of Human Neutrophils”. Histochemistry. 79 (1): 105–10. doi:10.1007/BF00494347. PMID 6196326. S2CID 785829.
  3. Crutchfield A, Diller K, Brand J (1999). “Cryopreservation of Chlamydomonas reinhardtii (Chlorophyta)”. European Journal of Phycology. 34 (1): 43–52. doi:10.1080/09670269910001736072.
  4. Hawkins BT, Egleton RD (2006). “Fluorescence imaging of blood–brain barrier disruption”. Journal of Neuroscience Methods. 151 (2): 262–7. doi:10.1016/j.jneumeth.2005.08.006. PMID 16181683. S2CID 31154215.
  5. Schürmann, B.; Wu, X.; Dietzel, I. D.; Lessmann, V. (May 1997). “Differential modulation of AMPA receptor mediated currents by evans blue in postnatal rat hippocampal neurones”. British Journal of Pharmacology. 121 (2): 237–247. doi:10.1038/sj.bjp.0701125. ISSN 0007-1188. PMC 1564681. PMID 9154333.
  6. Price, C. J.; Raymond, L. A. (December 1996). “Evans blue antagonizes both alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate and kainate receptors and modulates receptor desensitization”. Molecular Pharmacology. 50 (6): 1665–1671. ISSN 0026-895X. PMID 8967991.
  7. Wittenburg, H.; Bültmann, R.; Pause, B.; Ganter, C.; Kurz, G.; Starke, K. (October 1996). “P2-purinoceptor antagonists: II. Blockade of P2-purinoceptor subtypes and ecto-nucleotidases by compounds related to Evans blue and trypan blue”. Naunyn-Schmiedeberg’s Archives of Pharmacology. 354 (4): 491–497. doi:10.1007/bf00168441. ISSN 0028-1298. PMID 8897453. S2CID 22823820.
  8. Venes, Donald. “Evans Blue”. Taber’s Cyclopedic Medical Dictionary. 21: 818.

External links

  • el-Sayed H, Goodall S, Hainsworth R (1995). “Re-evaluation of Evans blue dye dilution method of plasma volume measurement”. Clin Lab Haematol. 17 (2): 189–94. PMID 8536425.
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