Background: The mesolimbic dopamine (DA) projection from the ventral tegmental area to nucleus accumbens (nAc), a central part of the reward system, is activated by ethanol (EtOH) and other drugs of abuse. We have previously demonstrated that the glycine receptor in the nAc and its amino acid agonists may be implicated in the DA activation and reinforcing properties of EtOH. We have also reported that the glycine transporter 1 inhibitor, Org 25935, produces a robust and dose-dependent decrease in EtOH consumption in Wistar rats. The present study explores the interaction between EtOH and Org 25935 with respect to DA levels in the rat nAc.
Methods: The effects of Org 25935 (6 mg/kg, i.p.) and/or EtOH (2.5 g/kg, i.p.) on accumbal DA levels were examined by means of in vivo microdialysis (coupled to HPLC-ED) in freely moving male Wistar rats. The effect of Org 25935 on accumbal glycine output was also investigated.
Results: Systemic Org 25935 increased DA output in a subpopulation of rats (52% in Experiment 1 and 38% in Experiment 2). In Experiment 2, EtOH produced a significant increase in DA levels in vehicles (35%) and in Org 25935 nonresponders (19%), whereas EtOH did not further increase the DA level in rats responding to Org 25935 (2%). The same dose of Org 25935 increased glycine levels by 87% in nAc.
Conclusions: This study demonstrates that Org 25935, probably via increased glycine levels, (i) counteracts EtOH-induced increases of accumbal DA levels and (ii) increases basal DA levels in a subpopulation of rats. The results are in line with previous findings and it is suggested that the effects observed involve interference with accumbal GlyRs and are related to the alcohol consumption modulating effect of Org 25935.
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Brain Res Bull
October 2019
Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvarad ter 4, P.O. Box 370, H-1445 Budapest, Hungary.
Interneurons operating with glycine neurotransmitter are involved in the regulation of pain transmission in the dorsal horn of the spinal cord. In addition to interneurons, glycine release also occurs from glial cells neighboring glutamatergic synapses in the spinal cord. Neuronal and glial release of glycine is controlled by glycine transporters (GlyTs).
View Article and Find Full Text PDFJ Neural Transm (Vienna)
May 2017
Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
The glycine transporter-1 inhibitor Org25935 is a promising candidate in a treatment concept for alcohol use disorder targeting the glycine system. Org25935 inhibits ethanol-induced dopamine elevation in brain reward regions and reduces ethanol intake in Wistar rats. This study aimed to further characterise the compound and used ethanol consumption, behavioral measures, and gene expression as parameters to investigate the effects in Wistar rats and, as pharmacogenetic comparison, Alko-Alcohol (AA) rats.
View Article and Find Full Text PDFAlcohol Clin Exp Res
September 2014
Addiction Biology Unit, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
Background: Org 25935 is a glycine transporter inhibitor that increases extracellular glycine levels and attenuates alcohol-induced dopaminergic activity in the nucleus accumbens. In animal models, Org 25935 has dose-dependent effects on ethanol intake, preference, and relapse-like behavior without tolerance. The current study aimed to translate these animal findings to humans by examining whether Org 25935 prevents relapse in detoxified alcohol-dependent patients.
View Article and Find Full Text PDFAnesth Analg
October 2014
From the Department of Dental Science for Health Promotion, Division of Integrated Health Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan; Cancer Pathophysiology Division, National Cancer Center Research Institute, Tokyo, Japan; Department of Pharmacology, Faculty of Nursing, Hiroshima Bunka Gakuen University, Hiroshima, Japan; Department of Cell & Molecular Pharmacology, Division of Basic Life Science, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan; Pharmaceutical Education Support Center, Mukogawa Women's University, Nishinomiya, Hyogo, Japan; and Department of Pharmacotherapy, Pharmaceutical Sciences, Nihon Pharmaceutical University, Saitama, Japan.
Background: Recent studies have revealed the antinociceptive effects of glycine transporter (GlyT) inhibitors in neuropathic pain models such as sciatic nerve-injured and diabetic animals. Bone cancer can cause the most severe pain according to complex mechanisms in which a neuropathic element is included. Bone cancer modifies the analgesic action of opioids and limits their effectiveness, and thus novel medicament for bone cancer pain is desired.
View Article and Find Full Text PDFJ Clin Psychopharmacol
April 2014
From *Merck Sharp & Dohme, Oss, the Netherlands; and †Inventiv Health Clinical, Leusden, the Netherlands; and ‡Merck & Co, Inc, Rahway, NJ.
Using a selective glycine uptake inhibitor as adjunctive to second-generation antipsychotic (SGA) was hypothesized to ameliorate negative and/or cognitive symptoms in subjects with schizophrenia. Subjects with predominant persistent negative symptoms (previously stabilized ≥3 months on an SGA) were enrolled in a randomized, placebo-controlled trial to investigate adjunctive treatment with Org 25935, a selective inhibitor of type 1 glycine transporter, over 12 weeks in a flexible dose design. Org 25935 was tested at 4 to 8 mg twice daily and 12 to 16 mg twice daily versus placebo.
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