Pharmacological profile of vascular activity of human stem villous arteries.
INTRODUCTION
The function of the placental vasculature differs considerably from other systemic vascular beds of the human body. A detailed understanding of the normal placental vascular physiology is the foundation to understand perturbed conditions potentially leading to placental dysfunction.


METHODS
Behaviour of human stem villous arteries isolated from placentae at term pregnancy was assessed using wire myography. Effects of a selection of known vasoconstrictors and vasodilators of the systemic vasculature were assessed. The morphology of stem villous arteries was examined using IHC and TEM.


RESULTS
Contractile effects in stem villous arteries were caused by U46619, 5-HT, angiotensin II and endothelin-1 (p ≤ 0.05), whereas noradrenaline and AVP failed to result in a contraction. Dilating effects were seen for histamine, riluzole, nifedipine, papaverine, SNP and SQ29548 (p ≤ 0.05) but not for acetylcholine, bradykinin and substance P.


DISCUSSION
Stem villous arteries behave differently to vessels of the systemic vasculature and results indicate that the placenta is cut off from the systemic maternal vascular regulation. Particularly, endothelium-dependent processes were attenuated in the placental vasculature, creating a need to determine the role of the endothelium in the placenta in future studies.
['Sander|Katrin N|KN|', 'Ali|Tayyba Y|TY|', 'Warren|Averil Y|AY|', 'Hay|Daniel P|DP|', 'Broughton Pipkin|Fiona|F|', 'Barrett|David A|DA|', 'Khan|Raheela N|RN|']
D000328:Adult D001158:Arteries D005260:Female D006801:Humans D009213:Myography D010920:Placenta D011247:Pregnancy D014662:Vasoconstrictor Agents D014665:Vasodilator Agents
Human Stem villous arteries Placenta Pregnancy Wire myography Placental vessels Vascular function