AA41612

AA41612 is a melanopsin (Opn4) inhibitor with an IC₅₀ of 15.8 nM, a K_i of 0.43 nM, and a K_d of 0.28 nM. AA41612 competes with retinal for binding to melanopsin, blocks melanopsin activation, and inhibits melanopsin-mediated phototransduction processes without affecting rod- and cone-mediated responses. AA41612 attenuates light-induced melanopsin photocurrents, reduces light-induced cytoplasmic calcium elevation, and weakens high-irradiance pupillary light reflex in mice with induced classical photoreceptor degeneration. AA41612 can be used in studies related to migraine and photophobia^[1][2]. In Vitro: AA41612 (10-100 nM; 3 min) inhibits mouse melanopsin-mediated photocurrent in Xenopus oocytes with an IC₅₀ of 20 nM^[1]. In Vivo: AA41612 (10 mg/kg; i.p.; single dose) reduces the minor melanopsin-mediated component of high-irradiance pupillary light reflex by less than 15% at the highest tested irradiance in adult mice with induced classical photoreceptor degeneration^[2].