Monoamines

Norepinephrine is a monoamine neurotransmitter

Monoamines are a group of neurotransmitters and neuromodulators . They all contain an amino group which is linked to an aromatic ring via an ethylene group (-CH ₂ -CH ₂ -) . All monoamines are derivatives of aromatic amino acids such as:

• Phenylalanine
• Tyrosine
• Histidine
• Tryptophan
• Thyroid hormones
  • Triiodothyronine (T3)
  • Thyroxine (T4)

The monoamines are formed using the enzyme aromatic-L-amino acid decarboxylase (AADC).

Examples

• Catecholamines :
  • Dopamine (DA)
  • Norepinephrine (NA), norepinephrine (NE)
  • Adrenaline (A) [Epinephrine (Epi)]
• Serotonin (5-HT)
• Melatonin
• histamine
• Thyronamine

• Trace amines :
  • β-phenylethylamines (PEA, β-PEA)
  • Tyramine
  • Tryptamine

regulation

The monoamines are transported into or out of the cells by so-called monoamine transporters; in the outer cell membrane are responsible for the transport:

• Dopamine transporter (DAT)
• Serotonin Transporter (SERT)
• Norepinephrine Transporter (NET)

On the inner cell membrane are the:

• Vesicular monoamine transporter -1 (VMAT-1)
• Vesicular Monoamine Transporter-2 (VMAT-2)

After their release into the synaptic cleft, the monoamine neurotransmitters are deaminated by the monoamine oxidase and thus inactivated.