Hemopressin Binds to Cannabinoid Receptor and Reduces Perception of Pain

The psychoactive compound in marijuana that alters brain functioning can bind to at least two receptors found in the cells of the body, called cannabinoid receptors CB1 and CB2. Together, CB1, CB2, and the molecules produced by the body that normally bind to these two receptors (endocannabinoids) are called the endocannabinoid system. Studies have shown that the endocannabinoid system plays a role in inflammation, nerve pain, and disorders including Alzheimer’s disease, and would potentially make a good target for new treatments of these conditions. Researchers funded in part by NIDA have identified a peptide called hemopressin that binds to CB1 receptors and, when given to mice either by direct injection or orally, reduced the perception of pain without sedative effects or impairment of motor activity. The researchers caution that further studies are needed to understand what functions hemopressin may normally have in the body. However, they conclude, hemopressin has potential to serve as a template for the development of a novel pain therapy in the future. Heimann AS, Gomes I, Dale CS, Pagano RL, Gupta A, de Souza LL, Luchessi AD, Castro LM, Giorgi R, Rioli V, Ferro ES, Devi LA. Hemopressin is an inverse agonist of CB1 cannabinoid receptors. Proc Natl Acad Sci USA. 2007;104(51):20588–20593.