Endothelium dependent vasodilation refers to the production of nitric oxide by the endothelial cell. Nitric oxide is a strong vasodilator.

Constitutive means that something is synthesized at a constant level (this includes nNOS and eNos enzymes). Inducible enzymes is only present during pathological states such as inflammation (this will include INOS enzymes.

NO contributes to the fatal pathology of septic shock by causing hypotension due to excessive No mediated vasodilation.

Nitric oxide

NO binds to superoxide species, this can be cytotoxic This toxicity can be prevented by glutathione which protects cells.

NO stimulates the release of inflammatory prostaglandins by activating COX-2. This causes NO to be pro-inflammatory. Advantages thereof is: there is a increase in permeability, causing White blood cells to move through the endothelium to the site of action easily. Disadvantages is that an excess of NO production can cause acute inflammatory oedema which will lead to cell injury.

Parkinson’s disease, stroke.