Mediation by 5-HT2 receptors of 5-hydroxytryptamine-induced contractions of human placental vein

M. Antonieta Cruz, Victoria Gallardo, Patricia Miguel, Gonzalo Carrasco, Clemente González

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

1. In isolated human placental chorionic vein segments, 5-hydroxytryptamine (5-HT; 10-8 to 5 x 10-5 M) elicited concentration-dependent contractions with EC50 = 5.5 (5.2-5.7) x 10-8 M) and E(max) = 93.1 ± 7.3% of 75 mM KCl-induced contraction. 2. The agonist of 5-HT2 receptors, α-methyl-5-hydroxytryptamine, and the selective agonist of 5-HT1 receptors, N,N-dipropyl-5-carboxamidotryptamine and 5-carboxamidotryptamine, induced pronounced concentration related contractions, which reached 71.1 ± 6.0%, 53.0 ± 5.0% and 75.0 ± 7.8% at the highest dose tested, respectively. The agonist of 5-HT3 receptor, 2-methyl-5-hydroxytryptamine, reached a maximum averaging 36.7 ± 5.1% of the maximal response to KCl. 3. The 5-HT1 and 5-HT3 receptor antagonists, methiothepin and metoclopramide (10-7 to 10-6 M) did not alter the response to 5-HT. However, ketanserin (10-7 to 10-6 M), a 5-HT2 receptor antagonist, induced significant inhibition of the concentration-response curve to 5 HT. 4. Contractile responses to 5-carboxamidotryptamine and 2-methyl-5-hydroxytryptamine were not affected by methiothepin and metoclopramide, respectively, whereas ketanserin significantly attenuated the contractile response to these agonists. 5. In conclusion, our study shows that 5-HT2 receptors mediate contraction of the human placental vein with no obvious role for 5-HT1-like, or 5 HT3 receptors.

Original languageEnglish (US)
Pages (from-to)483-488
Number of pages6
JournalGeneral Pharmacology
Volume30
Issue number4
DOIs
StatePublished - Apr 1998
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Pharmacology

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