Chemical factors affecting VC/VD

• Chemical factors affecting VC/VD:

  • metabolic factors ie decrease in O2, decrease in nutrients, increase in K+, increase in H+, lactic acid, adenosine -> localised vasodilation e.g. during exercise
  • inflammatory mediators,, usually during tissue damage e.g. histamines, kinins and prostaglandins -> usually local vasodilation
  • nitric oxide -> powerful vasodilation, but short lived - released by endothelial cells
  • endothelins - one of the most powerful vasoconstrictors known - released by endothelial cells