Premium
Identification of 5‐hydroxytryptamine 1D binding sites in human brain membranes
Author(s) -
Peroutka Stephen J.,
Switzer Julie A.,
Hamik Anne
Publication year - 1989
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.890030109
Subject(s) - identification (biology) , membrane , human brain , binding site , chemistry , computational biology , neuroscience , biophysics , biology , biochemistry , botany
High‐affinity, specific 3 H‐5‐hydroxytryptamine (5‐HT) binding was analyzed in membrane homogenates of human frontal cortex, caudate, and globus pallidus. 5‐HT 1A and 5‐HT 1C binding sites were pharmacologically blocked using 100 nM 8‐hydroxy‐N,N‐dipropyl‐2‐aminotetralin (8‐OH‐DPAT) and 100 nM mesulergine, respectively. The majority of 5‐HT 1 sites remained in each of the three brain regions under these conditions. The pattern of nucleotide interactions with these binding sites (GppNHp = GTP = GDP > GMP = adenine nucleotides) suggests a possible linkage to a G protein. RU 24969 competition studies confirmed the absence of 5‐HT 1B binding sites in human cortex, caudate, and globus pallidus. Drug interactions with putative 5‐HT 1D binding sites in bovine caudate membranes correlated significantly with their affinities for human membrane recognition sites labeled by 3 H‐5‐HT in the presence of 100 nM 8‐OH‐DPAT + 100 nM mesulergine. We conclude that the majority of 3 H‐5‐HT‐labeled recognition sites in human cortex, caudate, and globus pallidus represent 5‐HT 1D binding sites.