Cannabinoid receptors

Currently, two cannabinoid receptors have been described (CB1 and CB2 receptors) that modulate ion channels and signaling pathways.

Cannabinoid receptors bind N-palmitoylethanolamine(PEA) and induce sedative, antiemetic and analgesic effects in the central nervous system. The CB1 receptor was previously known to occur only in the central nervous system, while CB2 receptors are found in peripheral blood cells and immune system tissues.

Meanwhile, both receptors have been detected in the skin. Of interest is the expression of both receptors on mast cells and unmyelinated C-nerve fibers, which play a role in the development of pruritus. For the treatment of chronic pruritus, topical cannabinoid agonists have been used in one study. These are said to have a mast cell-stabilizing function which consecutively inhibits the histamine release responsible for pruritus.

1. Stand S et al (2006) Topical cannabinoid agonists. An effective new possibility for treating chronic pruritus. dermatologist 57: 801-807