体外研究
Opioid drugs exert a wide spectrum of physiological and behavioral effects. These effects are mediated via membrane-bound receptors, of which the best characterized are the kappa, delta, and mu receptors. Naltrindole inhibits the proliferation of cultured human U266 MM cells in a time- and dose-dependent manner with an EC
50
of 16 μM. Treatment of U266 cells with naltrindole significantly decreases the level of the active, phosphorylated form of the kinases, extracellular signal-regulated kinase and Akt, which may be related to its antiproliferative activity. Naltrindole inhibits growth and induces apoptosis in the three characteristic SCLC cell lines, NCI-H69, NCI-H345, and NCI-H510. Naltrindole treatment reduces constitutive phosphorylation of Akt/PKB on serine 473 and threonine 308 in cells and also its downstream effectors glycogen synthase kinase-3β and the Forkhead transcription factors AFX and FKHR.
体内研究
Naltrindole significantly decreases tumor cell volumes in human MM cell xenografts in severe combined immunodeficient mice. In mice, naltrindole at 20 mg/kg s.c. antagonizes the δ-selective agonist effect of [D- Ser, Leu, Thr]enkephalin (DSLET) without blocking the antinociceptive effect of morphine or U50488H. Naltrindole is the only highly selective δ antagonist that is active upon peripheral administration. Acute naltrindole induces significant decreases in external and total ambulation (horizontal activity) and rearing behaviour (vertical activity), as well as a significant increase in grooming frequency. In animals chronically treated with naltrindole there is an increase in total ambulation one day after the discontinuation of the treatment.
