bovine adrenal medulla 22 peptide (bam22p) is a peptide with 22 amino acids which is one of the cleavage products of proenkephalin a, the precursor of leu- and met-enkephalin, in the adrenal medulla, with very potent opiate activity.
in the guinea-pig ileum assay, bam-22p has been shown to have typical and extraordinarily potent opioid activities antagonized by naloxone. the potency of bam-22p is 26 times that of met-enkephalin and 22 times that of b hendorphin. ic50 value of bam-22p in this tissue, 1.3 nm, makes it the most potent met-enkephalin relatives that discoveried so far. [1].
intrathecal (i.t.) administration of bam22 decreased nocifensive behavior scores, which measured as the sum of flinching and lifting/licking, in the first and second phases of the formalin test. such decrease was partially attenuated by systemic injection of naloxone. [2].
1.3 nm for opiate activity
[1] mizuno k, minamino n, kangawa k, matsuo h. a new family of endogenous "big" met-enkephalins from bovine adrenal medulla: purification and structure of docosa- (bam-22p) and eicosapeptide (bam-20p) with very potent opiate activity. biochem biophys res commun. 1980 dec 31;97(4):1283-90.
[2] hong y, dai p, jiang j, zeng x. dual effects of intrathecal bam22 on nociceptive responses in acute and persistent pain--potential function of a novel receptor. br j pharmacol. 2004 feb;141(3):423-30.
