What do you understand by the term “endothelium-dependent” vasodilation?  Explain.

It means vasodilation that takes place inside the endothelium. 

When we talk about the NOS enzyme, what is meant by “constitutive” and “inducible” enzymes and what are the pathological and physiological implications thereof?

Constitutive enzymes are continously synthesised, irrespective on if substrate is available or not. 

Inducible enzymes are released as a reaction to a stimulus. 

Because constitutive enzymes are continously produced they have a greater chance to be influenced by pathology than inducible enzymes. 

Explain how NO contributes to the fatal pathology of septic shock.

NO is produced during septic shock that causes vasodilation, which can cause the accumulation of blood in certain areas, hypotension and shock. This causes that less blood is available to important organs that can cause death. 

Which autacoids’ mechanism of action depends on effects on the guanylyl cyclase-cGMP system?

• Nitric oxide

NO may be toxic to the cell.  Which mechanisms are available to the body to counter this detrimental effect of NO?

NOS enzyme inhibitors are released by the body that binds competitively to argenine binding sites in NOS and prevents the conversion of argenine to NO.

Name a way in which NO can act pro-inflammatory.  Give examples of where it will have advantages or disadvantages.

When an alien antigen enters the body, NO is synthesised. This is advantageous because immune cells can reach the antigen and deactivate it, but it also has a negative impact because vasodilation can lead to anaphylactic shock. 

In which possible neurological and psychiatric diseases is NO involved?  

Parkinson's and stroke