Autoregulatory reactions of the skeletal muscle arterioles to a decrease in arterial pressure

Internal radius, wall thickness, and blood flow rate are measured in ratm. cremaster arterioles of different orders of branching under normal and stepwise decreased arterial pressure. Two types of reactions to a 20% decrease in arterial pressure are observed: active autoregulatory reaction (42% vessels) and passive reaction (58%). It is shown that relative changes in the diameter of arterioles in autoregulatory and passive reactions depend on the relative thickness of arteriolar wall and becomes more pronounced as this parameter increases.[PUBLICATION ABSTRACT]