Different receptor subtypes mediate the dual presynaptic effects of 5-hydroxytryptamine on peripheral sympathetic neurones

E. Adler-Graschinsky, A. B. Elgoyhen, N. V. Butta

Research output: Contribution to journalArticle

Abstract

The aim of the present work was to characterize the presynaptic 5-HT receptors that mediate either the facilitation of the responses to nerve stimulation in the nicitating membrane of the cat or the inhibition of the responses to nerve stimulation in the guinea-pig atria. In the nicitating membrane of the cat, the shift to the left in the frequency-response curves produced by 5-HT (0.1 μM) was prevented by the 5-HT3 receptor antagonists, metoclopramide (1 μM) and MDL 72222 (0.01 μM). The facilitatory effect of 5-HT is also prevented by the 5-HT2 receptor antagonist, 0.01 μM ketanserin. Nevertheless, this drug reduced by itself the responses to both nerve stimulation and exogenous NA in the nictitating membrane. In the guinea-pig isolated atria, the inhibitory effect of 5-HT on the chronotropic responses to cardioaccelerans nerve stimulation was mimicked by the mixed 5-HT1(A) + 5-HT1(B) + 5-HT1(D) receptor agonist 5-carboxamidotryptamine (5-CT 0.1 and 1 μM). The 5-HT1(A) receptor agonist 8-OH-DPAT (0.1 and 1 μM) did not modify the responses of the atria to the nerve stimulation. The 5-HT2 receptor antagonists, ketanserin (0.01 and 0.1 μM) and cyproheptadine (1 μM), did not prevent the inhibitory effect of 5-HT in the guinea-pig atria. The present results suggest that the facilitatory effects of 5-HT in the nictitating membrane of the cat are linked to the activation of 5-HT3 receptors whereas the inhibitory effects observed in the guinea-pig atria are mediated by 5-HT1-like receptors.

Original languageEnglish (US)
Pages (from-to)3-13
Number of pages11
JournalJournal of Autonomic Pharmacology
Volume9
Issue number1
StatePublished - 1989
Externally publishedYes

ASJC Scopus subject areas

  • Neuroscience(all)
  • Pharmacology

Fingerprint Dive into the research topics of 'Different receptor subtypes mediate the dual presynaptic effects of 5-hydroxytryptamine on peripheral sympathetic neurones'. Together they form a unique fingerprint.

  • Cite this