Retina evokes biphasic relaxations in retinal artery unrelated to endothelium, KV, KATP, KCa channels and methyl palmitate

► Retinal tissue produces rapid and biphasic relaxations in retinal arteries. ► Biphasic relaxations are insensitive to the inhibitors of endothelial vasodilators. ► Biphasic relaxations are mediated by the release of retinal relaxing factor. ► Biphasic relaxation character may depend on different cellular mechanisms. ► KATP, KV and KCa channel activation do not mediate retinal relaxations.