engleski

Binding of dihydroergosine to 5-HT1A receptors of human and rat brain

Interaction of the ergot alkaloid dihydroergosine with the binding of (H-3)8-hydroxy-2-(di-n-propylamino)tetralin ((3)H8-OH-DPAT), a selective agonist for 5-HT1A binding sites, to hippocampal membranes isolated from human and rat brain was studied. Competition binding experiments showed that dihydroergosine is a potent displacer of (H-3)8-OH-DPAT binding at brain 5-HT1A receptors of both species. Scatchard analysis of (H-3)8-OH-DPAT binding to rat hippocampal membranes in the presence of dihydroergosine revealed that this ergot compound markedly decreases the number and the affinity of hippocampal (H-3)8-OH-DPAT labelled binding sites. Preincubation of rat hippocampal membranes for 180 min with dihydroergosine (2 nmol dm(-3)) completely prevented the binding of (H-3)8-OH-DPAT (2 nmol dm(-3)). The data suggest that dihydroergosine is approximately as potent a ligand as 8-OH-DPAT for the hippocampal 5-HT1A receptors from human and rat brains, although their kinetics of association and dissociation are apparently different. [References: 41]

ergot alkaloid; 5-HT1A receptors; (3H)8-OH-DPAT binding; hippocampus; human brain; rat brain

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