Novel mechanism for counter-regulatory responses to hypoglycemia

Abstract

In the central nervous system, especially in the hypothalamus, the energy status in the body is assessed by glucose-sensing neurons since glucose is the major fuel in the central nervous system. Glucose sensing mechanisms also have a significant role in prevention of hypoglycemic bouts. In a recent report, Fan and colleagues proved a novel type of glucose-exited neurons which detect hypoglycemia through decreasing glucose entry via SGLT1.

Figure 1

Glucose‐sensing mechanisms in the central nervous system. Glucose‐excited (GE) neurons express adenosine triphosphate (ATP)‐sensitive potassium channel (K_ATP) and/or sodium glucose co‐transporter 1 (SGLT1). Glucose‐inhibited (GI) neurons express adenosine monophosphate (AMP)‐activated protein kinase (AMPK). AMPK increases nitric oxide (NO) production. Glucose (Glc) is imported into neurons and astrocytes through glucose transporters (GLUTs) or SGLT1. A part of Glc is metabolized to lactate (Lac) in astrocytes. Lac is exported from astrocytes, and imported into neurons through monocarboxylic acid transporters (MCTs).