Significance of HMP Pathway

Biochemistry - Significance Of HMP Pathway

1. Significance Of HMP Pathway V.S.RASHMI PRIYEM ULTRA’S BEST Dental Science College Rashmi Priyem Saravanan

2. Metabolic Role of NADPH formed by HMP Shunt Pathway 1. Required for reductive biosynthesis, such as fatty acid, cholesterol and steroids 2. Free radical scavenging 3. RBC membrane integrity 4. Prevention of formation of met-hemoglobin 5. Detoxification 6. Preserving transparency of lens of eye 7. Bactericidal activity of macrophages 8. Production of ribose and deoxyribose for DNA and RNA synthesis Rashmi Priyem Saravanan

3. 1. Pathway is Operating in Following Organs : i . Liver ii. Adipose tissue iii. Adrenal cortex iv. Mammary glands v. Testes and ovaries vi. RBCs vii. Lens of eye A. The Oxidative Phase Of The Pathway Is Seen In T he Above Organs, Where NADPH Generation Is Required For Lipid Synthesis Or Steroid Synthesis. B. The Non-oxidative Phase Is Present In All Tissues, And So Synthesis Of Ribose Is Possible In All Tissues Of The Body. Rashmi Priyem Saravanan

4. 2. Generation of Reducing Equivalents The major metabolic role of the pathway is to provide cytoplasmic NADPH For Reductive Biosynthesis Of Fatty Acids Cholesterol Steroids Rashmi Priyem Saravanan

5. 3. Free Radical Scavenging Free radicals (super oxide, hydrogen peroxide) are continuously produced in all cells. These will destroy DNA, proteins, fatty acids and all biomolecules , and in turn cells are destroyed. The free radicals are inactivated by enzyme systems containing Superoxide Dismutase (SOD) Glutathione Peroxidase (POD) Glutathione Reductase (GR) Rashmi Priyem Saravanan

6. 4. Erythrocyte Membrane Integrity NADPH is required by the RBC to keep the glutathione in the reduced state . In turn, reduced glutathione will detoxify the peroxides and free radicals formed within the RBC . NA DPH, glutathione and glutathione reductase together will preserve the integrity of RBC membrane. Rashmi Priyem Saravanan

7. Free Radical Scaving Enzymes SOD = Super Oxide Dismutase POD =Glutathione Peroxidase GSH = Glutathione GR= Glutathione Reductase GPD= Glucose-6-phosphate Dehydrogenase Rashmi Priyem Saravanan

8. 5. Prevention of Met- Hemoglobinemia NADPH is also required to keep the iron of hemoglobin in the reduced (ferrous) state To prevent the accumulation of met-hemoglobin Met-hemoglobin cannot carry oxygen. Rashmi Priyem Saravanan

9. 6. Detoxification of Drugs Most of the drugs and other foreign substances are detoxified by the liver, with the help of NADPH. Rashmi Priyem Saravanan

10. 7. Lens of Eye Maximum concentration of NADPH is seen in lens of eye. NADPH is required for preserving the transparency of lens. Rashmi Priyem Saravanan

11. 8. Macrophage Bactericidal Activity NADPH is required for production of reactive oxygen species (ROS) (superoxide anion radical) by macrophages to kill bacteria MPO = myeloperoxidase Rashmi Priyem Saravanan

12. 9. Availability of Ribose Ribose and deoxyribose are required for DNA and RNA synthesis. Ribose is also necessary for nucleotide coenzymes. Rashmi Priyem Saravanan

13. 10. What about ATP? ATP is neither utilized nor produced by the HMP shunt pathway. Cells do not use the shunt pathway for energy production. Rashmi Priyem Saravanan