Endomorphin 1 acetate, a high affinity, highly selective agonist of the μ-opioid receptor ( K i : 1.11 nM), displays reasonable affinities for kappa 3 binding sites, with K i value between 20 and 30 nM. Endomorphin 1 acetate has antinociceptive properties. In Vitro Endomorphin 1 acetate inhibits Forskolin (1 μM) stimulated cyclic AMP formation with a pIC 50 value of 8.03 in In CHOμ cells . Endomorphin 1 (1-10 μM) acetate increases interleukin-8 secretion in Caco-2 cells. Endomorphin 1 (1 μM) acetate inhibits excitatory transmission in adult rat substantia gelatinosa neurons. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo Endomorphin 1 (i.c.v.) acetate shows antinociceptive properties in mice, with an ED 50 value of 6.16 nM. Endomorphin 1 (50 μg/kg, i.v., rats) acetate alleviates myocardial ischemia/reperfusion injury (MIRI) by inhibiting the inflammatory response. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: ICR mice. Dosage: 6.16 nM (ED 50 ) Administration: Intracerebroventricularly (i.c.v.) injection Result: Inhibited dose-dependently the tail-flick response. Animal Model: Rats. Dosage: 50 μg/kg Administration: Intravenously following LAD ligation for 25 min, subsequently the LAD was reperfused for 120 min. Result: Alleviated MIRI by reducing the production of free radicals. Dncreased LDH and CK-MB activities. Increased SOD activity and decreased MDA content. Decreased IL-6 and TNF-α plasma content. Form:Solid IC50& Target:μ Opioid Receptor/MOR 1.11 nM (Ki)