Formulation: A lyophilized powder
Formal Name: L-tyrosyl-L-prolyl-L-phenylalanyl-L-phenylalaninamide, trifluoroacetate salt
Purity: ≥95%
Formula Markup: C32H37N5O5 • XCF3COOH
Formula Weight: 571,7
Shelf life (days): 1460
Notes: Endomorphin 2 is an endogenous neuropeptide and μ-opioid receptor agonist (Ki = 0.69 nM) that has analgesic, negative reinforcing, and gastrointestinal properties.{43252,43253} It is found in the spinal cord and, to a lesser extent, in the brain.{43255} It is selective for μ- over δ- and κ-opioid receptors (Kis = 9,233 and 5,240 nM, respectively).{43252} Endomorphin 2 also binds to mouse brain membranes and rat recombinant μ-opioid receptors expressed in CHO cells (Kis = 1.37 and 0.58 nM, respectively).{43253} It inhibits cAMP accumulation induced by forskolin in CHO cells expressing rat recombinant μ-opioid receptors and in SH-SY5Y human neuroblastoma cells (IC50s = 7.08 and 7.76 nM, respectively).{43254} In mice, endomorphin 2 increases analgesia in a radiant heat tail-flick assay in mice following intracerebroventricular (i.c.v.) or intrathecal administration (ED50s = 1.99 and 3.81 μg, respectively) and induces conditioned place aversion when administered intracerebroventricularly at a dose of 10 μg.{43253} It also decreases gastrointestinal transit time in mice when administered intracerebroventricularly at a dose of 3 μg.{43253}