Mechanisms of cell injury

• one of the most important environmental changes that causes cell injury is lack of oxygen

• heart attacks are the number one cause of death in this society and they are caused by lack of oxygen supply to the myocardium

• lack of oxygen will ultimately cause cell injury because the cell can’t produce ATP anymore

• normally, in oxidative phosphorylation, you make about 30 ATPs per glucose molecule. when you cut that off, you get two ATPs, a reduction in energy production by a factor of 15

• so, cutting off oxygen leads to a big decrease in ATP production

• on the other hand, if injury is mediated by radiation, chemicals (including drugs), or reperfusion, many activated oxygen species are created (O₂⁺, H₂O₂, OH^.)

• ischemia is important for heart attacks and strokes; activated oxygen species are important in a variety of inflammatory diseases

Category: Medical Subject Notes , Pathology Notes