These compounds initiate lipid peroxidation which acts like a detergent on cells. Arachidonic acid is further degraded into substances called the eicosanoids by enzymes known as monooxygenases. The eicosanoids, prostaglandins, thromboxanes and leukotrienes, are responsible for cascades that lead to further vasoconstriction, clotting and edema. The eicosanoids are also responsible for activating signals that attract scavenger cells. These cells remove the dead cells but may also further damage ischemic cells.
Calcium also activates the enzyme that forms nitric oxide in cells.
Nitric oxide is a free radical which can diffuse to other cells and cause significant neuronal injury or death. Calcium can also activate destructive enzymes such as proteases or nucleases which attack and destroy various parts of the cell. Water and chloride ions follow, causing cells to swell. Glial cells have a large capacity for sequestering free ions and water from the extracellular environment. This may play a protective role in delaying edema formation in neurons.