Dopamine

Category: neurotransmitter

Aliases: 3,4-Dihydroxyphenethylamine, DA

Pharmacological Mechanism

catecholamine synthesis synthesised from tyrosine via L-DOPA (tyrosine hydroxylase, rate-limiting) → dopamine (AADC). Acts at dopamine receptor signaling D1-like (D1, D5) and D2-like (D2, D3, D4) GPCRs. Nigrostriatal pathway → motor control; mesolimbic → reward; mesocortical → executive function; tuberoinfundibular → prolactin suppression. Depleted in Parkinson's (nigrostriatal loss).

Dosing Guidelines

• IV: Typical 8 mcg (Range: 2–20 mcg)

Target Organ Systems

• nervous
• endocrine

Interactions

• Levodopa (synergistic): L-DOPA is the BBB-crossing precursor; converted to dopamine by AADC in CNS and periphery.
• Tyrosine (synergistic): Dietary precursor via tyrosine hydroxylase (rate-limiting).
• Norepinephrine (synergistic): Upstream catecholamine precursor via DβH.

Pathways It Modulates

• Catecholamine synthesis (substrate) — product of DOPA decarboxylation; precursor to NE/E

Chemical Identifiers

• PubChem CID: 681
• Formula: C8H11NO2
• Molecular weight: 153.18 g/mol
• InChIKey: VYFYYTLLBUKUHU-UHFFFAOYSA-N
• SMILES: C1=CC(=C(C=C1CCN)O)O