LY2444296 is an orally bioavailable, high-affinity and selective short-acting kappa opioid receptor (KOPR) antagonist, with a Ki value of ∼1 nM. LY2444296 exhibits anti-anxiety like effects[1][2].
[1]. Huang P, et al. Two short-acting kappa opioid receptor antagonists (zyklophin and LY2444296) exhibited different behavioral effects from the long-acting antagonist norbinaltorphimine in mouse anxiety tests. Neurosci Lett. 2016 Feb 26;615:15-20. [2]. Valenza M, et al. "Effects of the novel relatively short-acting kappa opioid receptor antagonist LY2444296 in behaviors observed after chronic extended-access cocaine self-administration in rats". Psychopharmacology (Berl). 2017 Aug;234(15):2219-2231.