[3H]Sumatriptan binding sites in human brain: regional-dependent labelling of 5-HT1D and 5-HT1F receptors.
The general properties of [3H]sumatriptan binding sites in postmortem human brain tissue sections are described. High concentrations of autoradiographic grains were seen in globus pallidus = substantia nigra > cortex > putamen > hippocampus. While 5-HT (5-hydroxytryptamine) displaced in all regions more than 90% of [3H]sumatriptan binding, the level of binding inhibited by 5-CT (5-carboxamidotryptamine) varied in each region. Although the binding inhibited by 5-CT in some regions such as globus pallidus and substantia nigra was equivalent to that obtained with 5-HT, in cortical areas, such as frontal cortex and hippocampus, a substantial level of binding insensitive to 5-CT was seen. In addition, in membrane binding assays, 10 nM metergoline displaced most [3H]sumatriptan specific binding in striatum and only 16% in frontal cortex. In the human brain sumatriptan binds to at least two 5-HT1 receptors, 5-HT1D and 5-HT1F.
Pascual
J
J
Department of Physiology and Pharmacology, University of Cantabria, Santander, Spain.
Del Arco
C
C
Romón
T
T
Del Olmo
E
E
Pazos
A
A
D000328:Adult; D001345:Autoradiography; D001665:Binding Sites; D001921:Brain / Q000187:drug effects*; D005625:Frontal Lobe / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects; D006801:Humans; D008875:Middle Aged; D011985:Receptors, Serotonin / Q000187:drug effects* / Q000378:metabolism; D018170:Sumatriptan / Q000494:pharmacology*
D011985:Receptors, Serotonin; D018170:Sumatriptan