The efflux of purine nucleobases and nucleosides from the rat brain

Neurosci Lett. 2002 Jan 25;318(2):65-8. doi: 10.1016/s0304-3940(01)02478-8.

Abstract

The efflux of purine nucleobases and their nucleosides from the rat brain was investigated using the brain efflux index (BEI) method. Calculated BEI values showed that purine nucleobases had very rapid initial efflux after the intracerebral injection, which was followed by the slower efflux due to the intracellular trapping of labelled molecules and confirmed by the capillary depletion technique. The efflux of ribonucleosides was much slower than the efflux of nucleobases and the structure of the sugar moiety seemed to be important, since a significant difference in the efflux velocity between ribo- and deoxyribonucleosides was observed. The results of self- and cross-inhibition studies suggested that the efflux of test molecules was saturable and that purines shared the same transport system on the abluminal side of the blood-brain barrier.

MeSH terms

  • Adenosine / blood
  • Adenosine / cerebrospinal fluid
  • Animals
  • Blood-Brain Barrier / drug effects*
  • Blood-Brain Barrier / physiology
  • Brain / drug effects*
  • Brain / metabolism
  • Carbon Radioisotopes / metabolism
  • Carrier Proteins / drug effects*
  • Carrier Proteins / physiology
  • Deoxyribonucleosides / blood
  • Deoxyribonucleosides / cerebrospinal fluid
  • Extracellular Space / drug effects
  • Extracellular Space / metabolism
  • Guanosine / blood
  • Guanosine / cerebrospinal fluid
  • Hypoxanthine / blood
  • Hypoxanthine / cerebrospinal fluid
  • Injections, Intraventricular
  • Inosine / blood
  • Inosine / cerebrospinal fluid
  • Purine Nucleosides / blood
  • Purine Nucleosides / cerebrospinal fluid
  • Purine Nucleosides / metabolism*
  • Purines / metabolism*
  • Rats
  • Rats, Wistar

Substances

  • Carbon Radioisotopes
  • Carrier Proteins
  • Deoxyribonucleosides
  • Purine Nucleosides
  • Purines
  • Guanosine
  • Hypoxanthine
  • Inosine
  • Adenosine