Evidence of functional beta-adrenoceptors in the cutaneous vasculature

During a hyperthermic challenge, skin blood flow (SkBF) increases primarily through activation of the cutaneous active vasodilator system. However, mechanisms through which activation of this system elevates SkBF remain unknown. In this project, we sought to identify whether functional beta-adrenoceptors exist on cutaneous vessels and, if present, whether these receptors play an important role in elevating SkBF during a hyperthermic challenge. In protocol 1, SkBF was assessed over two intradermal microdialysis probes. Initially, both probes were perfused with lactated Ringer solution. Probe A was then perfused with a 200 microM solution of the beta-adrenoceptor agonist isoproterenol while probe B was perfused with a 1.7 mM solution of the beta-adrenoceptor antagonist propranolol. Isoproterenol perfusion significantly increased SkBF from 17.7 +/- 2.4 to 70.8 +/- 13.2 perfusion units (PU; P 0.05). ...