Effects of oxygenation and luminal flow on human placenta chorionic plate blood vessel function

Aim: The human fetoplacental vasculature has been suggested to be a low resistance/high flow system, but the mechanisms by which this state is achieved are unclear. Methods: This study assessed the effects of intraluminal flow and local oxygenation on isolated human placental chorionic plate arteries and veins at term using pressure myography. Results: Chorionic plate arteries and veins exhibit myogenic tone. A small but significant arterial vasodilatation was observed following exposure to hypoxia; chorionic plate veins contracted to a similar hypoxic stimulus. Under physiological conditions of pressure and oxygenation, increased luminal flow induced contraction in both chorionic plate arteries and veins. [Correction added after online publication 15th November 2011: 'induced vasodilatation' has been changed to 'induced contraction'] Conclusions: Human fetoplacental vascular tone can be manipulated by local physical factors.