Effects of stimulation of mu opioid and nociceptin/orphanin FQ peptide (NOP) receptors on alcohol drinking in rhesus monkeys

Neuropsychopharmacology. 2019 Jul;44(8):1476-1484. doi: 10.1038/s41386-019-0390-z. Epub 2019 Apr 10.

Abstract

Alcohol use disorder (AUD) persists as a devastating public health problem; widely effective pharmacological treatments are needed. Evidence from rodent models suggests that stimulating brain receptors for the neuropeptide nociceptin/orphanin FQ (NOP) can decrease ethanol drinking. We characterized the effects of the mu opioid peptide (MOP) receptor agonist buprenorphine and the buprenorphine analog (2S)-2-[(5R,6R,7R,14S)-N-cyclopropylmethyl-4,5-epoxy-6,14-ethano-3-hydroxy-6 methoxymorphinan-7-yl]-3,3-dimethylpentan-2-ol (BU08028), which stimulates MOP and NOP receptors, in a translational nonhuman primate model of AUD. Rhesus monkeys drank a 4% ethanol solution 6 h per day, 5 days per week via an operant behavioral panel in their home cages. To assess behavioral selectivity, monkeys responded via a photo-optic switch to earn food pellets. After characterizing the acute effects of BU08028 (0.001-0.01 mg/kg, i.m.) and buprenorphine (0.003-0.056 mg/kg, i.m.), the drugs were administered chronically using a model of pharmacotherapy assessment that incorporates clinical aspects of AUD and treatment. Acutely, both drugs decreased ethanol drinking at doses that did not affect food-maintained responding. During chronic treatment, effects of BU08028 and buprenorphine were maintained for several weeks without development of tolerance or emergence of adverse effects. BU08028 was ~0.5 and 1.0 log units more potent in acute and chronic studies, respectively. The selective NOP receptor agonist SCH 221510 also selectively decreased ethanol intakes when given acutely (0.03-1.0 mg/kg, i.m.), whereas the MOP antagonist naltrexone (1.7-5.6 mg/kg, i.m.) decreased both ethanol intake and food pellets delivered. These data demonstrate that bifunctional MOP/NOP agonists, which may have therapeutic advantages to MOP-selective drugs, can decrease alcohol drinking in nonhuman primates.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alcohol Drinking / prevention & control*
  • Animals
  • Azabicyclo Compounds / pharmacology
  • Buprenorphine / analogs & derivatives*
  • Buprenorphine / pharmacology*
  • Dose-Response Relationship, Drug
  • Eating / drug effects
  • Macaca mulatta
  • Male
  • Naltrexone / pharmacology
  • Nociceptin Receptor
  • Receptors, Opioid / agonists*
  • Receptors, Opioid, mu / agonists*

Substances

  • 2-(N-cyclopropylmethyl-4,5-epoxy-6,14-ethano-3-hydroxy-6-methoxymorphinan-7-yl)-3,3-dimethylpentan-2-ol
  • 8-(bis(2-methylphenyl)methyl)-3-phenyl-8-azabicyclo(3.2.1)octan-3-ol
  • Azabicyclo Compounds
  • Receptors, Opioid
  • Receptors, Opioid, mu
  • Buprenorphine
  • Naltrexone
  • Nociceptin Receptor