Regional differences in depolarization-induced release of gamma-hydroxybutyrate from rat brain slices.
gamma-Hydroxybutyrate (GHB), an endogenous compound in mammalian brain which possesses important neuroregulatory properties, has been proposed as a neurotransmitter. The present report concerns the heterogeneous regional characteristics of depolarization-induced gamma-[3H]hydroxybutyrate ([3H]GHB) release in rat brain slices. The Ca2+-dependent component of [3H]GHB release in cerebellum and pons-medulla, areas with low concentrations of GHB binding sites, is only about 23% of that in hippocampus, striatum and frontoparietal cortex, all areas rich in binding sites. In addition, veratridine-induced release of [3H]GHB in cerebellum and pons-medulla is only 16% of that measured in hippocampus, striatum and frontoparietal cortex. These findings add support to the suggested neurotransmitter role of GHB in the forebrain and suggest a purely metabolic role for this compound in more posterior regions of brain where both binding sites and Ca2+-dependent release mechanisms are absent.
Vayer
P
P
Centre de Neurochimie du C.N.R.S. and INSERM U44, Strasbourg, France.
Maitre
M
M
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D002118:Calcium / Q000502:physiology; D006885:Hydroxybutyrates / Q000378:metabolism*; D066298:In Vitro Techniques; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012978:Sodium Oxybate / Q000378:metabolism*; D014701:Veratridine / Q000494:pharmacology
D006885:Hydroxybutyrates; D014701:Veratridine; D012978:Sodium Oxybate; D011188:Potassium; D002118:Calcium