Vasoactive Molecules (Amines)

✓ Amine✓ Peptide✓ Lipids

✓ Amine✓ Peptide✓ Lipids

Released by mast cells

Causes vasodilation and blood vessel leakage.

The effects of this vasoactive molecule are mediated by its multiple receptors.

H1 and H2 receptors are expressed on nerve cells, smooth muscle cells, endothelial cells, neutrophils, eosinophils, monocytes, dendritic cells and B & T cells.

When histamine binds with H1 receptor it stimulates endothelial cells to produce nitric oxide which is potent vasodilator.

When histamine binds with H1 receptor it stimulates endothelial cells to produce nitric oxide which is potent vasodilator.

Also caused vascular leakage which lead to fluid accumulation and local edema.

Also caused vascular leakage which lead to fluid accumulation and local edema.

5-hydroxytryptamine (5-HT)

Derivative of amino acid tryptophan

Released by mast cells of rodents and large domestic herbivores.

Causes vasoconstriction which may result in the increase of blood pressure, except in cattle where it is a vasodilator