Hemoglobin alpha in the blood vessel wall

作者：Butcher Joshua T; Johnson Tyler; Beers Jody; Columbus Linda; Isakson Brant E^*

来源：Free Radical Biology and Medicine, 2014, 73: 136-142.

DOI：10.1016/j.freeradbiomed.2014.04.019

• Hemoglobin
• Hemoglobin alpha
• alpha-Thalassemia
• Myoendothelial junction
• Cytochrome b(5) reductase 3
• Nitric oxide
• Free radicals

Hemoglobin has been studied and well characterized in red blood cells for over 100 years. However, new work has indicated that the hemoglobin alpha subunit (Hb alpha) is also found within the blood vessel wall, where it appears to localize at the myoendothelial junction (MEJ) and plays a role in regulating nitric oxide (NO) signaling between endothelium and smooth muscle. This discovery has created a new paradigm for the control of endothelial nitric oxide synthase activity, nitric oxide diffusion, and, ultimately, vascular tone and blood pressure. This review discusses the current knowledge of hemoglobin's properties as a gas exchange molecule in the bloodstream and extrapolates the properties of Hb alpha biology to the MEJ signaling domain. Specifically, we propose that Hb alpha is present at the MEJ to regulate NO release and diffusion in a restricted physical space, which would have powerful implications for the regulation of blood flow in peripheral resistance arteries.

• 出版日期2014-8