Characterization of sodium-independent beta-alanine binding to cerebral cortical membranes from 7-day-old and adult mice.
The sodium-independent binding of beta-alanine to cerebral cortical membranes from adult (3- and 12-month-old) and developing (7-day-old) mice was characterized for the first time. The binding was saturable in each age group, consisting of only one component. The affinity for beta-alanine was highest and the number of available binding sites greatest in young animals. The binding was not affected by strychnine, but inhibited by beta-alanine itself, glycine, L-alanine and L-serine, the IC50 values being lower in immature mice. Glycine was shown to be a competitive inhibitor. The binding was also inhibited, albeit only in adults, by N-methyl-D-aspartate receptor antagonists acting at the glycine modulatory site and by some GABAergic substances. It is concluded that even though beta-alanine may possess binding sites of its own, particularly in the immature cerebral cortex, beta-alanine could at least partly bind to strychnine-insensitive glycine sites in the N-methyl-D-aspartate receptor complex.
Saransaari
P
P
Tampere Brain Research Center, Department of Biomedical Sciences, University of Tampere, Finland.
Oja
S S
SS
D000818:Animals; D002540:Cerebral Cortex / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D005260:Female; D018755:GABA Agonists / Q000494:pharmacology; D005998:Glycine / Q000819:agonists; D066298:In Vitro Techniques; D008297:Male; D008566:Membranes / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D012044:Regression Analysis; D012964:Sodium / Q000502:physiology*; D015091:beta-Alanine / Q000378:metabolism*
D018755:GABA Agonists; D015091:beta-Alanine; D012964:Sodium; D005998:Glycine