Henk M. De Feyter1, Kevin Behar1,
Lester R. Drewes2, Robin A. de Graaf1, Douglas L.
Rothman1
1Diagnostic Radiology, Yale University,
New Haven, CT, United States; 2Biochemistry & Molecular
Biology, University of Minnesota, Duluth, MN, United States
Repetitive
iatrogenic hypoglycemic events lead to brain adaptations resulting in failing
counterregulatory response and lack of warning symptoms (hypoglycemia
unawareness) normally associated with low blood glucose levels. Increased
blood-brain barrier lactate transport via upregulated monocarboxylic acid
transporter 1 (MCT1) has been suggested as an adaptation induced by
repetitive hypoglycemia. Increased lactate uptake and oxidation could
(partially) replace glucose thereby contribute to hypoglycemia unawareness
and failing counterregulatory response. We used 1H-[13C]
MRS combined with [3-13C]-lactate infusion during hypoglycemia to
investigate the role of increased lactate transport and/or metabolism in the
brain of a rat model with ketogenic diet-induced upregulation of MCT1.