Vasodilator

A vasodilator is a substance that causes blood vessels in the body to grow slightly wider by relaxing the smooth muscle[?] in the vessel wall. This will reduce blood pressure (since there is more room for the blood) and might allow blood to flow around a clot. Several vasodilators are used as drugs.

Natural vasodilators and drugs that exploit them:

• Nitric oxide
  • Glycerol trinitrate[?]
  • Viagra
• Adrenaline and noradrenaline vasodilate arterioles of the skeletal muscles[?]. (By acting on beta-2 adrenergic receptors.) These chemicals cause vasocontriction[?] elsewhere.
  • Alpha-blockers[?] and Beta-blockers (block the constricting effect of adrenaline.
• Prostacyclin[?] (PGI₂) as well as other prostaglandins.
• Adenosine
  • Adenocard - this is primarily used as an anti-arrhythmic.
• Histamine[?]
  • Complement proteins C3a, C4a and C5a work by triggering histamine release from mast cells and basophils[?].
• Atrial natriuretic peptide[?] (ANP) - a weak vasodilator.
• Bradykinin[?]
• Platelet activating factor[?] (PAF)