Modulation of myogenic responsiveness by CO2 in rat diaphragmatic arterioles: role of the endothelium

The role of PCO2 on the myogenic response of diaphragmatic arterioles to elevated transmural pressure was analyzed in isolated rodent arterioles. Exposure of rodent diaphragmatic arterioles to changes in transluminal pressure indicated the role of the vascular endothelium in mediating arteriolar myogenic response to a broad range of transmural pressures. Furthermore, hypercapnia enhanced arteriolar vasoconstrictor response to increasing levels of transmural pressure indicating the minor role of PCO2 in the regulation of skeletal muscle blood flow.