Corneal endothelium ion exchange pump are inhibited by: (AIIMS Nov 2007)
|A||Anaerobic glycolysis inhibition|
|B||Anaerobic glycolysis activation|
|C||cGMP Phosphodiesterase inhibition|
|D||Interference with electronic chain transport.|
1. Anaerobic glycolysis activation leads to pyruvate formation and 2 molecules of ATP .
2. This pyruvate is further metabolized by citric acid cycle to CO2 and water and 36 molecules of ATP.
3. But if there is hypoxia or increased anaerobic condition persisting, this pyruvate is converted to lactate by lactate dehydrogenase leading to metabolic acidosis in the aqueous. .
4. This leads to structural and functional alterations in the endothelium, hence interference with its ion exchange pump.
They have 2 primary functions
1. Barrier function: This depends upon normal levels of calcium and glutathione. Calcium helps in maintaining the junctional complexes and glutathione protects the cornea from free radical injury helping is both barrier and metabolic function.
2. Endothelial ion transport by endothelial metabolic pump: