Inhibitory effect of erythropoietin on contractility of human chorionic plate vessels.
OBJECTIVE
Placenta is a major source of erythropoietin production in the fetus; hypoxia is associated with elevated erythropoietin levels in the fetal circulation. We investigated fetoplacental vascular reactivity after exposure to erythropoietin in vitro.


METHODS
Third-order chorionic plate arteries from human term placentae were incubated in culture medium with or without erythropoietin (3 U/mL) for 24 hours. Vessels were mounted in a myograph for isometric tension recording, and their responses to vasopressors and vasorelaxants were studied.


RESULTS
Contractile responses to endothelin-1 and the thromboxane analogue U46619 were decreased in erythropoietin-exposed vessels compared with controls. Relaxant responses to the nitric oxide donor sodium nitroprusside and the phosphodiesterase inhibitor papaverine were not influenced by erythropoietin.


CONCLUSIONS
Exposure to elevated levels of erythropoietin has an inhibitory effect on contractile responses in human placental chorionic plate arteries. We speculate that this may improve fetoplacental perfusion in hypoxic fetuses with elevated erythropoietin production.
Jain
Venu
V
Institute of Reproductive and Developmental Biology, Imperial College London, London, UK. venu.jain@imperial.ac.uk
Lim
Maria
M
Longo
Monica
M
Fisk
Nicholas M
NM
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000328:Adult; D001158:Arteries / Q000187:drug effects / Q000502:physiology; D002823:Chorion / Q000098:blood supply*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004921:Erythropoietin / Q000494:pharmacology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010208:Papaverine / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011247:Pregnancy; D012996:Solutions; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D010726:Phosphodiesterase Inhibitors; D012996:Solutions; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D004921:Erythropoietin; D009599:Nitroprusside; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D010208:Papaverine; D011188:Potassium; D019331:NG-Nitroarginine Methyl Ester