Why does 2/3-DPG increase at altitude?

The rise in 2,3-diphosphoglycerate (2,3-DPG) content of human erythrocytes occurring at high altitude (caused by the rise in blood and red cell pH, respectively, and by the increased mean desaturation of hemoglobin) and the resulting right-hand shift of the oxyhemoglobin dissociation curve of blood serve to …

Under what circumstances would 2/3-DPG levels be high or low?

An increase in 2,3-DPG concentration is found in most conditions in which the arterial blood is undersaturated with oxygen, as in congenital heart and chronic lung diseases, in most acquired anaemias, at high altitudes, in alkalosis and in hyperphosphataemia.

What would happen to the concentration of 2/3-bpg and thus the oxygen binding curve of hemoglobin as a result of a deficiency in pyruvate kinase?

2,3-BPG has little effect on the binding of oxygen to hemoglobin at high Po2 but promotes release of O2 from hemoglobin at low Po2. It is formed in the RBC from the glycolytic intermediate, 1,3-BPG, by bisphosphoglycerate mutase.

What are the symptoms of a hexokinase deficiency?

Hexokinase Deficiency. Hexokinase deficiency is an autosomal recessive genetic disease characterized by nonspherocytic hemolytic anemia. Jaundice, splenomegaly, pallor and constitutional symptoms such as lethargy and fatigue are main symptoms.

Why is hexokinase activity elevated in hemolytic anemia?

It is important to bear in mind that hexokinase activity should be elevated in patients with hemolytic disease, and that apparently normal hexokinase activity in the presence of hemolytic anemia may, in fact, represent hexokinase deficiency ( Valentine et al., 1967 ).

What happens to hemoglobin in a BPGM deficiency?

Deficiency of BPGM results in decreased levels of 2,3-BPG. The consequent left shift of the oxygen dissociation curve increases hemoglobin affinity for oxygen, thus resulting in decreased delivery of oxygen into the peripheral tissues and compensatory polycythemia.

How is hexokinase activity related to PFK activity?

Hexokinase activity is intimately related to that of PFK, because of the susceptibility of the former to product inhibition. In most tissues, glucose 6-phosphate (G6P) is in rapid equilibrium with fructose 6-phosphate, which in turn serves as substrate for PFK.