Exposure of primary cultured astrocytes for 3 days to 1 μM of either dopamine, serotonin or norepinephrine resulted in upregulation (25-34% increase in Bmax) of the peripheral-type benzodiazepine receptors (PBRs) labeled with [3H]Ro5-4864. A similar treatment with γ-aminobutyric acid [GABA] caused a 2-fold increase in the affinity (Kd) of [3H]Ro5-4864. The monoamines tested and GABA had no effect on the binding parameters of [3H]PK 11195, another selective PBR ligand. The present study indicates that Ro5-4864 binding sites are susceptible to regulation by specific neurotransmitters and provides further evidence for the distinction between Ro5-4864 and PK 11195 binding sites of the PBRs in cultured astrocytes.
- Peripheral benzodiazepine receptor
ASJC Scopus subject areas
- Developmental Biology
- Molecular Biology
- Clinical Neurology