'La barrière hémato-encéphalique (BHE) est une barrière anatomique qui filtre et contrôle le passage des substances sanguines et les empêche de passer librement du sang au liquide extra-cellulaire de la substance grise du Système Nerveux Central (SNC). Elle isole ainsi la substance grise du reste de l'organisme et lui permet d'avoir un milieu spécifique, différent du milieu intérieur du reste de l'organisme. Cependant 2% des molécules (nutriments, médicaments...) ou virus peuvent la traverser comme les virus adéno-associés.'
Extrait de http://fr.wikipedia.org/wiki/Barri%C3%A ... A9phalique
'La barrière hémato-encéphalique est une membrane qui sépare la circulation sanguine et le liquide céphalo-rachidien, le fluide dans lequel baigne le cerveau et la moelle épinière. Cette membrane permet d'éviter le passage d'un certain nombre de toxiques au niveau du système nerveux central (bactéries, toxines,etc.). Elle peut aussi gêner le passage de médicaments.'
Extrait de http://dictionnaire.doctissimo.fr/defin ... alique.htm
'Suite aux études précliniques, il s'avère que l'imatinib ne passe la barrière hémato-encéphalique que dans une faible mesure.'
Extrait de http://ch.oddb.org/fr/gcc/resolve/point ... hinfo,3121.
The Blood-Brain Barrier in Treating Chronic Myelogenous Leukemia and Glioblastoma with Imatinib
Richard E. Kast and Daniele Focosi,
Department of Psychiatry, University of Vermont,
Burlington, VT 05401, USA;
Division of Hematology, University of Pisa, 56126 Pisa, Italy;
‘Chronic myelogenous leukemia (CML) can be controlled for years with the tyrosine kinase inhibitor imatinib but because
imatinib poorly penetrates the blood-brain barrier (BBB), on occasion, the CML clone will thrive and evolve to an
accelerated phase in the resulting imatinib sanctuary within the central nervous system. In this, CML resembles glioblastoma
in that imatinib, which otherwise may be effective, cannot get to the tumor. Although a common street drug
of abuse, methamphetamine is Food and Drug Administration–approved and marketed as a pharmaceutical drug to
treat attention-deficit disorders. It has shown the ability to open the BBB in rodents. We have some clinical hints that it
may do so in humans as well. This short note presents three new points potentially leading to better tyrosine kinase
inhibition behind the BBB: 1) Pharmaceutical methamphetamine may have a useful role in treating both CML and
glioblastoma by allowing higher imatinib concentrations behind the BBB. 2) The old antidepressant and monoamine
oxidase inhibitor selegiline, used to treat Parkinson disease, is catabolized to methamphetamine. Selegiline, as a nonscheduled
drug,may therefore be an easier way to open the BBB, allowing more effective chemotherapy with tyrosine
kinases. 3) Dasatinib is a tyrosine kinase inhibitor with a spectrum of inhibition only partially overlapping that of
imatinib and a mechanism of tyrosine kinase inhibition that is different from that of imatinib. The two should be additive.
In addition, dasatinib crosses the BBB poorly, and it can therefore be expected to benefit from methamphetamine assisted entry.
Extrait de http://www.transonc.com/pdf/manuscript/ ... o09280.pdf