TY - JOUR
T1 - Mediation by 5-HT2 receptors of 5-hydroxytryptamine-induced contractions of human placental vein
AU - Cruz, M. Antonieta
AU - Gallardo, Victoria
AU - Miguel, Patricia
AU - Carrasco, Gonzalo
AU - González, Clemente
N1 - Funding Information:
This research was supported by FONDECYT Grant 1950925 and Grant 96.033.084-1.0 from the Dirección de Investigación, Universidad de Concepción, Chile. We are grateful to the physicians and midwives of the Service of Obstetrics and Gynecology at the Hospital G. Grant Benavente, for their cooperation in this study.
PY - 1998/4
Y1 - 1998/4
N2 - 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.
AB - 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.
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U2 - 10.1016/S0306-3623(97)00107-9
DO - 10.1016/S0306-3623(97)00107-9
M3 - Article
C2 - 9522163
AN - SCOPUS:0032034204
SN - 0306-3623
VL - 30
SP - 483
EP - 488
JO - General Pharmacology
JF - General Pharmacology
IS - 4
ER -