LY-320,135 is a drug used in scientific research which acts as a selective

antagonist An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, riv ...

of the cannabinoid receptor CB₁. It was developed by

Eli Lilly and Company Eli Lilly and Company is an American pharmaceutical company headquartered in Indianapolis, Indiana, with offices in 18 countries. Its products are sold in approximately 125 countries. The company was founded in 1876 by, and named after, Colonel ...

in the 1990s. LY-320,135 displays fairly good selectivity, with a

binding affinity In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. The etymology stems from ''ligare'', which means 'to bind'. In protein-ligand binding, the ligand is usually a mol ...

for CB₁ around 70x stronger than for CB₂, but both its potency and selectivity are modest compared to newer agents, and at higher doses it also binds to a range of non-cannabinoid receptors. However LY-320,135 is still fairly widely used in research, particularly for elucidating the mechanisms by which many CB₁ antagonists act as

inverse agonists In pharmacology, an inverse agonist is a drug that binds to the same receptor as an agonist but induces a pharmacological response opposite to that of the agonist. A neutral antagonist has no activity in the absence of an agonist or inverse ...

at higher doses.

References

Cannabinoids CB1 receptor antagonists Benzofuran ethers at the benzene ring Resorcinol ethers Aromatic ketones Benzonitriles Drugs developed by Eli Lilly and Company {{cannabinoid-stub