Mention the importance of HMP shunt and explain why enzyme deficiency of shunt causes hemolytic anemia.

Importance of HMP shunt:

a. Provides ribose sugar for synthesis of nucleotide and nucleic acid.

b. Provide NADPH to

·        Helps in reductive synthesis of fatty acid, steroid, cholesterol etc

·        Support detoxification of toxic water insoluble aromatic/aliphatic substances into water soluble less toxic or non toxic forms

·        Prevent hemolysis by facilitating antioxidant activity in RBC

·        Facilitate superoxide and free radical production in phagocytes through oxygen dependent myeloperoxidase system to kill bacteria and other pathogens

·        Helps in reduction of H₂O₂.

·        Helps in synthesis of NO and EDRF

c. It is alternative pathway of glucose oxidation.

Clinical consequence of G6PD deficiency:

Hemolytic anemia: here HMP shunt cannot continue to provide NADP2H because of the deficiency of its rate limiting enzyme G6PD. So hemolytic anemia happens to occur due to the failure of superoxide metabolism in RBC due to the lack of NADP2H.