Regulation of oxygen delivery to the body via hypoxic vasodilation - Kulandavelu et al. (2015)

Key Points

• The two-gas model of respiration (oxygen and carbon dioxide) is lacking in that it does not consider the importance of bioactive NO

• NO carried by the red blood cells is essential for blood flow and tissue oxygenation

The Breathing Diabetic Summary

We learned the importance of the nitric oxide (NO) that “rides” on the red blood cells (RBCs) in another PNAS paper from Zhang et al. (2015).  We also saw that this mechanism is disrupted in diabetics with high HbA1c.  The current authors wrote a short commentary on the importance of NO for blood flow regulation, which complements those two papers nicely.

The biggest takeaway from this short paper was their argument against the two-gas (oxygen and carbon dioxide) model of respiration.  They succinctly and convincingly convey the importance of NO: We cannot just consider O2 and CO2, we need to consider how bioactive NO controls blood flow, relaxing the blood vessels and improving blood flow in areas of tissue hypoxia.  See the Zhang et al. (2015) for a thorough description of this mechanism.

Another standout from this paper is that they specifically mention the clinical relevance of this “NO discovery” to diabetes and other diseases in which the release of bioactive NO from the red blood cells is disrupted.  Now that we know the mechanism, we can begin figuring out ways to treat it.  For us, let’s not wait on some new drug, let’s start by improving our HbA1c and breathing nasally 24/7. 

Journal Reference:

Shathiyah Kulandavelu, Wayne Balkan, and Joshua M. Hare, (2015) Regulation of oxygen delivery to the body via hypoxic vasodilation, PNAS, 112, 20, 6254-6255.