Conducted Vascular Responses: Communication across the Capillary Bed

摘要: Abstract Conducted vasomotor responses are important for the effective distribution of blood flow, although mechanism by which these initiated is not well understood. ATP, a substance released from circulating red cells in response to low P O 2 and pH, two conditions associated with decreased supply relative demand, has been shown initiate conducted vasodilation following its intraluminal application first second order arterioles. Since such pH would most likely occur on venous side vasculature, we evaluated arteriolar capillary networks ATP into venules Saran-covered hamster cheek pouch retractor muscle using vivo video microscopy. Intraluminal 40 400 pl 10 −6 M resulted dose-dependent increases diameter >450 μm upstream site application. These changes were accompanied significant cell flux. In capillaries, flux doubled administration. NO was previously determined be involved vascular arterioles, role responses. We found that systemic administration l -NAME prior eliminated any this effect reversed -arginine. data suggest venular microvasculature, may serve distributing perfusion alterations supply.