The kinetics of hypoxanthine efflux from the rat brain

Brain Res. 2001 Apr 27;899(1-2):248-50. doi: 10.1016/s0006-8993(01)02115-1.

Abstract

The brain efflux of radiolabelled hypoxanthine in the rat was rapid in the first minute after injection [K(eff)(i)=0.21+/-0.06 min(-1)], which was saturable with a V(max)=13.08+/-0.81 nM min(-1) g(-1), and a high K(m,app) (67.2+/-13.4 microM); the K(i,app) for inosine was 31.5+/-7.6 microM. Capillary depletion analysis indicated that hypoxanthine accumulates in neurons and glia with the time. From cross-inhibition studies with different purines and pyrimidines, it suggests that these molecules could also be important substrates for this carrier.

MeSH terms

  • Animals
  • Biological Transport / physiology
  • Brain / metabolism*
  • Hypoxanthine / pharmacokinetics*
  • Injections, Intraventricular
  • Kinetics
  • Rats
  • Rats, Wistar

Substances

  • Hypoxanthine