The kinetics of hypoxanthine efflux from the rat brain.
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.
Redzic
Z B
ZB
Institute of Biochemistry, School of Medicine, Pasterova 2, Belgrade, Yugoslavia.
Isakovic
A
A
Segal
M B
MB
Thomas
S A
SA
Rakic
L M
LM
D000818:Animals; D001692:Biological Transport / Q000502:physiology; D001921:Brain / Q000378:metabolism*; D019271:Hypoxanthine / Q000493:pharmacokinetics*; D007276:Injections, Intraventricular; D007700:Kinetics; D051381:Rats; D017208:Rats, Wistar
D019271:Hypoxanthine