Tuesday, February 12, 2013

beta-metilamino-L-alanina

Se as Cianobactérias são tão frequentes e estão por toda a parte, não poderiam explicar tanta doença neurológica de origem incerta?

BMAA neurotoxic effects

Degenerative locomotor diseases had been described in animals grazing on cycad species, fueling interest in a possible link between the plant and the etiology of ALS/PDC . Subsequent laboratory investigations discovered the presence of BMAA. BMAA induced severe neurotoxicity in rhesus macaques, including:[3]
There are reports that low BMAA concentrations can selectively kill cultured motor neurons from mouse spinal cords. In the motor neurons, BMAA activates AMPA-kainate glutamate receptors and boosted production of oxygen radicals.[2]

[edit]Worldwide concerns

The presence of BMAA in cyanobacteria, among the most populous organisms in the world, has raised concerns that humans worldwide may be exposed to levels of BMAA that could be potentially harmful. Cyanobacteria from soil and water samples collected around the world produce BMAA, giving rise to speculative biomagnification in food chains.[2] Scientists have also found that newborn rats treated with BMAA showed early neurotoxicity and impaired learning and memory as adults [6]

References

  1. ^ Cox, P.A., S.A. Banack, S.J. Murch, U. Rasmussen, G. Tien, R.R. Bidigare, J.S. Metcalf, L.F. Morrison, G.A. Codd, B. Bergman (2005). "Diverse taxa of cyanobacteria produce β-N-methylamino-L-alanine, a neurotoxic amino acid". Proceedings of the National Academy of Sciences of the United States of America 102: 5074–5078. doi:10.1073/pnas.0501526102PMID 15809446.
  2. a b c d Miller, G. (2006). "Guam's Deadly Stalker: On the Loose Worldwide?". Science 313: 428–431. doi:10.1126/science.313.5786.428PMID 16873621.
  3. a b Spencer, P.S., P.B. Nunn, J. Hugon, A.C. Ludolph, S.M. Ross, D.N. Roy, and R.C. Robertson (1987). "Guam amyotrophic lateral sclerosis-parkinsonism-dementia linked to a plant excitant neurotoxin". Science31 (237): 517–522. doi:10.1126/science.3603037PMID 3603037.
  4. ^ http://discovermagazine.com/2011/may/22-seafood-toxins-causing-als-alzheimers-parkinsons/article_view?b_start:int=2&-C=
  5. ^ http://www.sciencedaily.com/releases/2012/02/120223182516.htm=
  6. ^ Karlsson O, Roman E, Berg AL, Brittebo EB. (2011). "Early hippocampal cell death, and late learning and memory deficits in rats exposed to the environmental toxin BMAA (β-N-methylamino-L-alanine) during the neonatal period". Behav Brain Res 219: 310-320. doi:10.1016/j.bbr.2011.01.056PMID 21315110.
  7. Deborah Mash « CBS Miami

    miami.cbslocal.com/.../deborah-m... - 
    Sharks Unearth Clues Into Human Diseases. As a top marine researcher, Dr. Neil Hammerschlag, scours the oceans in search of sharks. She studies the ...

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