Oxygen Transport to Tissue XXX pp 301-306
Ketones Suppress Brain Glucose Consumption
- Cite this paper as:
- LaManna J.C. et al. (2009) Ketones Suppress Brain Glucose Consumption. In: Liss P., Hansell P., Bruley D.F., Harrison D.K. (eds) Oxygen Transport to Tissue XXX. Advances in Experimental Medicine and Biology, vol 645. Springer, Boston, MA
The brain is dependent on glucose as a primary energy substrate, but is capable of utilizing ketones such as β-hydroxybutyrate (βHB) and acetoacetate (AcAc), as occurs with fasting, prolonged starvation or chronic feeding of a high fat/low carbohydrate diet (ketogenic diet). In this study, the local cerebral metabolic rate of glucose consumption (CMRglu; μM/min/100g) was calculated in the cortex and cerebellum of control and ketotic rats using Patlak analysis. Rats were imaged on a rodent PET scanner and MRI was performed on a 7-Tesla Bruker scanner for registration with the PET images. Plasma glucose and βHB concentrations were measured and 90-minute dynamic PET scans were started simultaneously with bolus injection of 2-Deoxy-2[18F]Fluoro-D-Glucose (FDG).The blood radioactivity concentration was automatically sampled from the tail vein for 3 min following injection and manual periodic blood samples were taken. The calculated local CMRGlu decreased with increasing plasma BHB concentration in the cerebellum (CMRGlu = -4.07*[BHB] + 61.4, r² = 0.3) and in the frontal cortex (CMRGlu = - 3.93*[BHB] + 42.7, r² = 0.5). These data indicate that, under conditions of ketosis, glucose consumption is decreased in the cortex and cerebellum by about 10% per each mM of plasma ketone bodies.
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