Relationship between Blood Flow and Vascular Volume in Skeletal Muscle

Abstract

Increased blood flow, induced by raised perfusion pressure or as a post-ischemic hyperemia response, was associated with proportional volume change. When, after ischemia, reactive hyperemia was prevented by restoring perfusion to control flow, muscle volume returned to, but did not exceed, control volume. The contractile state of the capacitance vessels is therefore unaffected by ischemia, and variations in vascular volume accompanying changes in blood flow reflect changes in transmural pressure in the venules and veins. A substantial increase in venous pressure was needed to induce a volume increase matching that recorded during increased blood flow.

Key Words:

• Ischemia
• hyperemia
• plethysmography