Ketone bodies not utilised by:
Ref: Harper's Illustrated Biochemistry, 27th edition. Page 190 and Lippi ncotts Biochemistry, 3rd edition. Page 486Explanation:"Unlike fatty acids, ketone bodies can be used by the brain f but not by cells, such as red blood cells, that lack mitochondria) and, thus are important fuels during a fast. The liver lacks the ability to degrade ketone bodies, and so synthesizes them specifically for the peripheral tissues." Ref: Lippincott's Biochemistry', 3rd edition. Page 486Substrate utilized by various organs in different statesOrganFed StateFastingStarvationBrainGlucoseGlucoseKetone bodiesHeartFatly acidFatty acidKetone bodiesLiverGlucoseFatty acidAmino acidMusclesGlucoseFatty acidFatty acidKETOLYSISUtilization of ketone bodies.Site:o Mitochondriao Extra hepatic tissue,Tissues:o Heart.o Brain (especially when starving)o Skeletal muscleo Renal cortex.Ketones are NOT utilized by:o RBC - S ince it does NOT contain mitochondria.o Liver - Since it does NOT contain thiophorase enzyme.Note:Liver is the ONLY organ which produces ketone bodies and releases into blood, but it lacks the enzyme responsible (Thiophorase)for their degradation and utilization. This is the reason why liver does not utilize ketone bodies.
Brain
RBC
Heart
Skeletal muscle
Oxidation of Fatty acids: Ketogenesis