Serotonin 5‐HT1D Receptors in Human Prefrontal Cortex and Caudate: Interaction with a GTP Binding Protein

Katharine Herrick‐Davis, Milt Titeler, Sigrun Leonhardt, Robert Struble, Donald Price

Research output: Contribution to journalArticlepeer-review

Abstract

Abstract: Radioligand binding studies were performed to characterize serotonin 5‐HT1D receptors in postmortem human prefrontal cortex and caudate homogenates. [3H]5‐HT binding, in the presence of pindolol (to block 5‐HT1A and 5‐HT1B receptors) and mesulergine (to block 5‐HTlc receptors), was specific, saturable, reversible, and of high affinity. Scatchard analyses of [3H]5‐HT‐labeled 5‐HT1D sites in human prefrontal cortex produced a KD value of 4.2 nM and Bmax of 126 fmol/mg protein. In competition experiments, 8‐hydroxydipropylaminotetralin, trifluoromethylphenylpiper‐azine, mesulergine, 4‐bromo‐2,5‐dimethoxyphenyliso‐propylamine, and ICS 205–930 had low affinity for [3H]5‐HT‐labeled 5‐HT1D sites, indicating that the pharmacology of the 5‐HT1D site is distinct from that of previously identified 5‐HT1A, 5‐HT1B, 5‐HTlc, 5‐HT2, and 5‐HT3 sites. 5‐HT1D sites in human brain have a similar pharmacology to the 5‐HT1D sites previously identified in rat, porcine and bovine brains. Guanyl nucleotides, guanosine 5′‐O‐(3‐thiotriphosphate) (GTP‐γ‐S) and guanosine 5′‐(β,γ‐imido)‐triphosphate (Gpp(NH)p), modulated the binding of [3H]5‐HT to 5‐HT1D sites, whereas adenyl nucleotides had no effect. These findings are supportive of the presence of serotonin 5‐HT1D receptors in human prefrontal cortex and caudate which appear to be coupled to a GTP binding protein.

Original languageEnglish (US)
Pages (from-to)1906-1912
Number of pages7
JournalJournal of Neurochemistry
Volume51
Issue number6
DOIs
StatePublished - Dec 1988

Keywords

  • 5‐HT receptors
  • Guanyl nucleotides
  • Serotonin

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

Fingerprint Dive into the research topics of 'Serotonin 5‐HT<sub>1D</sub> Receptors in Human Prefrontal Cortex and Caudate: Interaction with a GTP Binding Protein'. Together they form a unique fingerprint.

Cite this