DAMGO TFA (78123-71-4(Free base)) is a potent and selective agonist of the Mu-opioid receptor and an analgesic that stimulates calcium-activated adenylate cyclase-associated cAMP production and induces TGF-beta1 expression at the protein and mRNA levels.

μ opioid receptor:NA

METHODS: HEK293 cells were transfected with the MOR-FLAG plasmid, and after morphine treatment (10 μM) for 6 days, the cells were treated with 1 μM DAMGO, and the localization of MOR was detected by immunofluorescence analysis after 30 and 60 min.
RESULTS In HEK293 cells, DAMGO treatment stimulated MOR internalization after 30 min and stimulated MOR recycling to the membrane after 1 hr. Morphine does not cause significant MOR internalization or down-regulation and readily induces tolerance; DAMGO counteracts this effect by enhancing endocytosis of the receptor, thereby reversing morphine-induced antinociceptive tolerance and restoring its analgesic efficacy. [1]
METHODS: Whole cell digests prepared from TF-1 cells in the absence or presence of two different concentrations of DAMGO (1 and 10 μM) were analyzed in westernblot experiments to investigate the effect of MOR-1 signaling on CXCR4 expression.
RESULTS Pretreatment with DAMGO (1 and 10 μM) for 24 h resulted in a change in the relative proportion of CXCR4+ cells to the low expression phenotype. [2]

METHODS: Male Sprague-Dawley rats (200-250 g) were injected with DAMGO by intrathecal administration of morphine (15 μg/10 μl twice a day for 6 days) on day 6 as a sedative, and tail-flick and paw withdrawal assays were performed 24, 48, and 72 hours later.
RESULTS Tolerance to morphine developed after 5 days of treatment; however, intravenous DAMGO restored sensitivity to morphine and potentiated morphine-induced acute antinociception after 24, 48 and 72 hours. [1]
METHODS: We studied the antinociceptive effects of DAMGO in naïve and morphine-tolerant mice by subcutaneously injecting male NMRI mice with 200 μmol/kg morphine twice daily for three days.
RESULTS After treatment with intravenous morphine, the mice were approximately four times more tolerant to intravenous DAMGO, i.e., the ED₅₀ value of DAMGO was four times higher than that of naive mice. [3]