Endothelial modulation of vascular tone and 5-hydroxytryptamine-induced responses in human chorionic arteries and veins.
1. In vitro studies were undertaken to evaluate the potential role of endothelium through release of vasodilators compounds on basal tension and on vasoconstrictor response induced by 5-hydroxytryptamine (5-HT) in chorionic arteries and veins rings from normotensive gestants. 2. N omega-nitro-L-arginine (100 microM) and methylene blue (10 microM) increased significantly the basal tension in chorionic arteries but not in veins. However, indomethacin (10 microM) inhibited the basal tension in both kinds of vessels. 3. The sensitivity to 5-HT was significantly lower in placental arteries than in veins. Removal of endothelium increased the sensitivity of placental arteries to 5-HT in 2.2-fold; however, in veins denudation had no significant effect. 4. N omega-nitro-L-arginine potentiated the 5-HT-induced tone in both types of vessels, but the increase of contraction was greater in chorionic arteries than in veins. However, indomethacin decreased the 5-HT-induced contractions in arteries and veins. 5. These results indicate that NO is more important than vasodilators prostanoids in the control of vascular tone and in 5-HT-induced placental contractile response.
Cruz
M A
MA
Departamento de Fisiología, Universidad de Concepción, Chile.
González
C
C
Gallardo
V
V
Albornoz
J
J
Munoz
M E
ME
Lagos
M
M
D000019:Abortifacient Agents / Q000494:pharmacology; D000892:Anti-Infective Agents, Urinary / Q000494:pharmacology; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001158:Arteries / Q000187:drug effects; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000502:physiology*; D011464:Epoprostenol / Q000494:pharmacology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007213:Indomethacin / Q000037:antagonists & inhibitors; D008751:Methylene Blue / Q000494:pharmacology; D009129:Muscle Tonus / Q000187:drug effects*; D009569:Nitric Oxide / Q000494:pharmacology; D019335:Nitroarginine; D010920:Placenta / Q000098:blood supply*; D011247:Pregnancy; D012701:Serotonin / Q000494:pharmacology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D014680:Veins / Q000187:drug effects
D000019:Abortifacient Agents; D000892:Anti-Infective Agents, Urinary; D016861:Cyclooxygenase Inhibitors; D017366:Serotonin Receptor Agonists; D019335:Nitroarginine; D009569:Nitric Oxide; D012701:Serotonin; D001120:Arginine; D011464:Epoprostenol; D008751:Methylene Blue; D007213:Indomethacin