Question

What are the three main mechanisms of cellular injury? Briefly describe each. Which of these is lost often irreversible

Answer 1

The three main mechanism of cellular damage are as follows:

1) Mitochondrial damage of cell - Increase of cytosolic calcium causes mitochondrial damage and it effects the increase in high conductance channel and leakage of cytochrome C into cytosol thus causes apoptosis of cell and also membrane damage of cell.

2) Membrane damage of cell- Influx of more calcium in the cell causes increase in membrane permeability and thus affects loss of calcium homeostasis. This occurs due to mitochondrial permeability due to leakage of it.

3) ATP depleted proximal tubules- Increase of intracellular free calcium and glycine plays an important role in decrease in ATP. This decrease in ATP causes increase in anaerobic glycolysis, failure of calcium pump, disruption of protein synthesis apparatus and thus protein misfolding occurs.

Due to increase in anaerobic glycolysis causes decrease of glycogen, increase in lactic acid and decrease in pH of the cell which effects clumping of nuclear chromatin. Influx of calcium causes damage in cellular components.

Damage to mitochondria and lysosomal membrane causes cells to become necrotic and thus it is responsible for irreversible damage.