The dopamine D1-, D5-like receptors

There are two main subgroups of dopamine receptor — D1-like and D2-like. The D1-like receptor family contains the D1 and D5 receptor subtypes and the D2-like family contains the D3 and D4 subtypes. The D1-like receptors are found throughout the brain and in blood vessels and smooth muscle. Dopamine D1-like receptors are coupled to stimulatory G-proteins and they have a stimulatory effect on neurotransmission when bound by an agonist. Regions of the brain with a high density of D1-like receptors tend have a low density of D2-like receptors whereas regions of the brain with a low D1-like receptor density have a high density of D2-like receptors.

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References

Other transmitters and modulators. In: Pharmacology, 4^th edition. Rang HP, Dale MM and Ritter JM. Edinburgh, UK: Harcourt Publishers Ltd, 2001:483–499.

Introduction to autonomic pharmacology. In: Basic and clinical pharmacology, 8^th edition. Katzung BG. USA: The McGraw Hill Companies, Inc, 2001:75–91.