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KETONE BODY METABOLISM
Dr. Vijay Marakala, MBBS, MD.
Assistant professor BIOCHEMISTRY SIMS & RC
Content
Definition Significance Synthesis
Utilization Ketosis
KETONE BODIES
DEF
INIT
ION Ketone bodies are
metabolic products that are produced in excess during excessive breakdown of fatty acids.
KETONE BODIES
Acetone
Acetoacetate β-hydroxybutyrate
Interrelationship of ketone bodies
SIGNIFICANCE
Alternate sources to glucose for energy
Production of ketone bodies under conditions of cellular energy deprivation
Utilization of ketone bodies by the brain
KETOGENESIS
Site Pathway
Regulation
SITE OF KETOGENESIS
Ketone bodies are synthesized only in liver
Acetyl-CoA Acetyl-CoA
Acetoacetyl-CoA
HMG-CoA
Acetoacetate
Acetone β-Hydroxybutyrate
CoA-SH
Acetyl-CoA
CoA-SHH2O
Acetyl-CoANADH+H+
NADCO2
Thiolase
HMG-CoA synthase
HMG-CoA lyaseβ-Hydroxybutyrate dehydrogenase
REGULATION OF KETOGENESIS
Level 1
Lipolysis INSULIN
GLUCAGON
Level 2
Entry of fatty acid to
mitochondriaCAT-I
Level 3
Oxidation of acetyl CoA
OXALOACETATE
KETONE BODY UTILIZATION
KETOLYSIS
Ketone bodies are not oxidized in the liver. Utilized in extrahepatic tissues such as brain, heart, skeletal
muscle and kidney
β-Hydroxybutyrate Acetoacetate
Acetoacetatyl CoA
Acetyl-CoA 2
Succinyl CoA
Succinate
CoA transferase
CoA-SH
Thiolase
KETOLYSIS
KETOSIS
Definition Causes Biochemical findings
Diagnosis management
KETOSIS - DEFINITION
Ketosis is a disorder of excessive production of
ketone bodies
KETOSIS - CAUSES
• Carbohydrate deprivation
Prolonged starvation
• Impaired uptake of glucose by the peripheral tissues
Uncontrolled diabetes mellitus
KETOSIS – BIOCHEMICAL FINDINGS
Ketonemia
Ketonuria
Acetone breath
Metabolic acidosis
Hyperkalemia
KETOSIS – BIOCHEMICAL DIAGNOSIS
• In plasma
β hydroxybutyrate
• In urine• Rothera’s test
Acetoacetate
KETOSIS – MANAGEMENT
Provision of glucose to the tissues
Starvation – carbohydrate ingestionDiabetes mellitus – glucose and insulin
Correction of acid-base and electrolyte imbalance
Bicarbonate administrationReverses hyperkalemia
Thank you