Effect of xamoterol on peripheral blood vessels in healthy subjects.

Changes in peripheral blood flow in response to increasing doses of xamoterol with or without a beta 2-adrenoceptor blocking agent were assessed in eight healthy volunteers. Xamoterol produced increases in femoral artery diameter, blood volume flow and velocity flow. In the brachial and posterior tibial arteries, systolic blood pressure rose, and in the brachial artery, diastolic blood pressure fell. None of these effects was affected by beta 2-adrenoceptor blockade. The actions of xamoterol on the circulation are consistent with direct stimulation of myocardial beta 1-adrenoceptors.