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