1
|
Walters AS, Li Y, Koo BB, Ondo WG, Weinstock LB, Champion D, Afrin LB, Karroum EG, Bagai K, Spruyt K. Review of the role of the endogenous opioid and melanocortin systems in the restless legs syndrome. Brain 2024; 147:26-38. [PMID: 37633259 PMCID: PMC10796165 DOI: 10.1093/brain/awad283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 07/23/2023] [Accepted: 08/01/2023] [Indexed: 08/28/2023] Open
Abstract
Restless legs syndrome (RLS) is responsive to opioid, dopaminergic and iron-based treatments. Receptor blocker studies in RLS patients suggest that the therapeutic efficacy of opioids is specific to the opioid receptor and mediated indirectly through the dopaminergic system. An RLS autopsy study reveals decreases in endogenous opioids, β-endorphin and perhaps Met-enkephalin in the thalamus of RLS patients. A total opioid receptor knock-out (mu, delta and kappa) and a mu-opioid receptor knock-out mouse model of RLS show circadian motor changes akin to RLS and, although both models show sensory changes, the mu-opioid receptor knock mouse shows circadian sensory changes closest to those seen in idiopathic RLS. Both models show changes in striatal dopamine, anaemia and low serum iron. However, only in the total receptor knock-out mouse do we see the decreases in serum ferritin that are normally found in RLS. There are also decreases in serum iron when wild-type mice are administered a mu-opioid receptor blocker. In addition, the mu-opioid receptor knock-out mouse also shows increases in striatal zinc paralleling similar changes in RLS. Adrenocorticotropic hormone and α-melanocyte stimulating hormone are derived from pro-opiomelanocortin as is β-endorphin. However, they cause RLS-like symptoms and periodic limb movements when injected intraventricularly into rats. These results collectively suggest that an endogenous opioid deficiency is pathogenetic to RLS and that an altered melanocortin system may be causal to RLS as well.
Collapse
Affiliation(s)
- Arthur S Walters
- Sleep Division, Department of Neurology, Vanderbilt University Medical Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Yuqing Li
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Brian B Koo
- Sleep Medicine Laboratory, VA Connecticut Health Care System, West Haven, CT 06516, USA
- Yale Center for Restless Legs Syndrome, Yale School of Medicine, New Haven, CT 06520, USA
| | - William G Ondo
- Department of Neurology, Methodist Hospital, Weill Cornell Medical School, Houston, TX 77030, USA
| | - Leonard B Weinstock
- Department of Internal Medicine, Washington University School of Medicine, St.Louis, MO 63130, USA
| | - David Champion
- Sydney Children's Hospital, Department of Pain Medicine, Randwick, NSW 2031, Australia
| | - Lawrence B Afrin
- Hematology/Oncology, AIM Center for Personalized Medicine, Purchase, NY 10577, USA
| | - Elias G Karroum
- Department of Neurology and Rehabilitation Medicine, The George Washington University School of Medicine and Health Sciences, George Washington University, Washington, D.C. 20052, USA
| | - Kanika Bagai
- Sleep Division, Department of Neurology, Vanderbilt University Medical Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Karen Spruyt
- Université Paris Cité, NeuroDiderot Inserm, Paris 75019, France
| |
Collapse
|
2
|
Lim SAO, Kang UJ, McGehee DS. Striatal cholinergic interneuron regulation and circuit effects. Front Synaptic Neurosci 2014; 6:22. [PMID: 25374536 PMCID: PMC4204445 DOI: 10.3389/fnsyn.2014.00022] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 09/05/2014] [Indexed: 01/11/2023] Open
Abstract
The striatum plays a central role in motor control and motor learning. Appropriate responses to environmental stimuli, including pursuit of reward or avoidance of aversive experience all require functional striatal circuits. These pathways integrate synaptic inputs from limbic and cortical regions including sensory, motor and motivational information to ultimately connect intention to action. Although many neurotransmitters participate in striatal circuitry, one critically important player is acetylcholine (ACh). Relative to other brain areas, the striatum contains exceptionally high levels of ACh, the enzymes that catalyze its synthesis and breakdown, as well as both nicotinic and muscarinic receptor types that mediate its postsynaptic effects. The principal source of striatal ACh is the cholinergic interneuron (ChI), which comprises only about 1-2% of all striatal cells yet sends dense arbors of projections throughout the striatum. This review summarizes recent advances in our understanding of the factors affecting the excitability of these neurons through acute effects and long term changes in their synaptic inputs. In addition, we discuss the physiological effects of ACh in the striatum, and how changes in ACh levels may contribute to disease states during striatal dysfunction.
Collapse
Affiliation(s)
| | - Un Jung Kang
- Department of Neurology, Columbia University New York, NY, USA
| | - Daniel S McGehee
- Committee on Neurobiology, University of Chicago Chicago, IL, USA ; Department of Anesthesia and Critical Care, University of Chicago Chicago, IL, USA
| |
Collapse
|
3
|
Kivell BM, Ewald AWM, Prisinzano TE. Salvinorin A analogs and other κ-opioid receptor compounds as treatments for cocaine abuse. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2014; 69:481-511. [PMID: 24484985 DOI: 10.1016/b978-0-12-420118-7.00012-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Acute activation of kappa-opioid receptors produces anti-addictive effects by regulating dopamine levels in the brain. Unfortunately, classic kappa-opioid agonists have undesired side effects such as sedation, aversion, and depression, which restrict their clinical use. Salvinorin A (Sal A), a novel kappa-opioid receptor agonist extracted from the plant Salvia divinorum, has been identified as a potential therapy for drug abuse and addiction. Here, we review the preclinical effects of Sal A in comparison with traditional kappa-opioid agonists and several new analogs. Sal A retains the anti-addictive properties of traditional kappa-opioid receptor agonists with several improvements including reduced side effects. However, the rapid metabolism of Sal A makes it undesirable for clinical development. In an effort to improve the pharmacokinetics and tolerability of this compound, kappa-opioid receptor agonists based on the structure of Sal A have been synthesized. While work in this field is still in progress, several analogs with improved pharmacokinetic profiles have been shown to have anti-addictive effects. While in its infancy, it is clear that these compounds hold promise for the future development of anti-addictive therapeutics.
Collapse
Affiliation(s)
- Bronwyn M Kivell
- School of Biological Sciences, Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Amy W M Ewald
- School of Biological Sciences, Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Thomas E Prisinzano
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas, USA.
| |
Collapse
|
4
|
Prisinzano TE. Natural products as tools for neuroscience: discovery and development of novel agents to treat drug abuse. JOURNAL OF NATURAL PRODUCTS 2009; 72:581-7. [PMID: 19099466 PMCID: PMC2788013 DOI: 10.1021/np8005748] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Much of what we know about the neurosciences is the direct result of studying psychoactive natural products. Unfortunately, there are many gaps in our understanding of the basic biological processes that contribute to the etiology of many CNS disorders. The investigation of psychoactive natural products offers an excellent approach to identify novel agents to treat CNS disorders and to find new chemical tools to better elucidate their biological mechanisms. This review will detail recent progress in a program directed toward investigating psychoactive natural products with the goal of treating drug abuse by targeting kappa opioid receptors.
Collapse
Affiliation(s)
- Thomas E Prisinzano
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, USA.
| |
Collapse
|
5
|
Prisinzano TE, Tidgewell K, Harding WW. Kappa opioids as potential treatments for stimulant dependence. AAPS J 2005; 7:E592-9. [PMID: 16353938 PMCID: PMC2751263 DOI: 10.1208/aapsj070361] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Accepted: 05/30/2005] [Indexed: 12/25/2022] Open
Abstract
Stimulant abuse is a major problem in the United States and the development of pharmacological treatments for stimulant abuse remains an important therapeutic goal. Classically, the "dopamine hypothesis" has been used to explain the development of addiction and dependence of stimulants. This hypothesis involves the direct increase of dopamine as the major factor in mediating the abuse effects. Therefore, most treatments have focused on directly influencing the dopamine system. Another approach, which has been explored for potential treatments of stimulant abuse, is the use of kappa opioid agonists. The kappa receptor is known to be involved, via indirect effects, in synaptic dopamine levels. This review covers several classes of kappa opioid ligands that have been explored for this purpose.
Collapse
Affiliation(s)
- Thomas E Prisinzano
- Division of Medicinal & Natural Products Chemistry, College of Pharmacy, The University of Iowa, Iowa City, Iowa 52242, USA.
| | | | | |
Collapse
|
6
|
Marin C, Bové J, Bonastre M, Tolosa E. Effect of acute and chronic administration of U50,488, a kappa opioid receptor agonist, in 6-OHDA-lesioned rats chronically treated with levodopa. Exp Neurol 2003; 183:66-73. [PMID: 12957489 DOI: 10.1016/s0014-4886(03)00107-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To evaluate the possible involvement of kappa opioid receptor-mediated mechanisms in levodopa-induced motor fluctuations, we have investigated the effects of U50,488, a selective kappa opioid agonist, on levodopa-induced motor alterations in rats with unilateral 6-OHDA lesion. Acute and chronic administration of U50,488 has been studied to evaluate the possible reversion or prevention of these levodopa effects. In a first set of experiments, rats were treated with levodopa (25 mg/kg with benserazide, twice daily, ip) for 22 days and, on Day 23 U50,488 (0.5, 1, or 3 mg/kg, i.p.) was administered immediately before levodopa. In a second set of experiments, rats were treated daily for 22 days with levodopa and U50,488 (1 or 3 mg/kg/day, i.p.). The duration of the rotational behavior induced by chronic levodopa decreased after 22 days (P < 0.05). Acute administration of U50,488 on Day 23 reversed this effect when low doses were administered (P < 0.05). Chronic U50,488 administration did not prevent the shortening in response duration induced by levodopa. Our results demonstrate that the kappa opioid receptor agonist U50,488 reverses but does not prevents levodopa-induced motor alterations in parkinsonian rats. These results suggest a role for kappa opioid receptor-mediated mechanisms in the pathophysiology of levodopa-induced motor response complications. These findings suggest that the stimulation of kappa opioid receptors might confer clinical benefit to parkinsonian patients under levodopa therapy suffering from motor complication syndrome.
Collapse
Affiliation(s)
- C Marin
- Laboratori de Neurologia Experimental, Fundació Clínic, IDIBAPS, Villarroel 170, 08036 Barcelona, Spain.
| | | | | | | |
Collapse
|
7
|
Soukara S, Maier CA, Predoiu U, Ehret A, Jackisch R, Wünsch B. Methylated analogues of methyl (R)-4-(3,4-dichlorophenylacetyl)- 3-(pyrrolidin-1-ylmethyl)piperazine-1-carboxylate (GR-89,696) as highly potent kappa-receptor agonists: stereoselective synthesis, opioid-receptor affinity, receptor selectivity, and functional studies. J Med Chem 2001; 44:2814-26. [PMID: 11495592 DOI: 10.1021/jm0108395] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Analogues of the kappa-receptor agonist methyl (R)-4-(3,4-dichlorophenylacetyl)-3-(pyrrolidin-1-ylmethyl)piperazine-1-carboxylate (GR-89,696, 6) bearing an additional methyl substituent in the side chain are synthesized and evaluated for their kappa-receptor affinity and selectivity. A key step in the synthesis is the stereoselective reductive amination of the ketones 9, 18, and 19 with pyrrolidine and NaBH(3)CN, which succeeds only in the presence of the Lewis acid Ti(OiPr)(4). Whereas the BOC-substituted ketone 9 affords the unlike and like diastereomers of 10 in a ratio of 70:30, the diastereoselectivity during the reductive amination of the butyl and phenyl substituted ketones 18 and 19 is enhanced to 85:15 (butyl derivative) and >95:<5 (phenyl derivative) in favor of the unlike diastereomers. In receptor binding studies using the radioligand [(3)H]U-69,593 the (S,S)-configured methyl carbamate (S,S)-14 reveals the highest kappa-receptor affinity (K(i) = 0.31 nM) within this series, even exceeding the lead kappa-agonist 6 (GR-89,696). A slightly reduced kappa-receptor affinity is observed with the propionamide (S,S)-13 (K(i) = 0.67 nM). The kappa-receptor affinity of piperazines with acyl or alkoxycarbonyl residues at both nitrogen atoms (11, 13, 14) decreases in the order (S,S) > (R,R) > (S,R) > (R,S). The methyl carbamate (S,S)-14 discloses a unique activity profile also binding at mu-receptors in the subnanomolar range (K(i) = 0.36 nM). In a functional assay, i.e., by measuring acetylcholine release in rabbit hippocampus slices, the agonistic effects of the methyl carbamate (S,S)-14 and the propionamide (S,S)-13 are demonstrated. Only weak kappa- and mu-receptor affinities are found with the butyl- and phenyl-substituted piperazines 22 and 23. However, considerable sigma(1)-receptor affinity is determined for the enantiomeric, unlike-configured butyl derivatives (R,S)-22 and (S,R)-22 with K(i)-values of 40.2 nM and 81.0 nM, respectively.
Collapse
MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/chemistry
- Acetylcholine/metabolism
- Animals
- Binding Sites
- Brain/metabolism
- Electric Stimulation
- Guinea Pigs
- Hippocampus/metabolism
- In Vitro Techniques
- Piperazines/chemical synthesis
- Piperazines/chemistry
- Piperazines/metabolism
- Piperazines/pharmacology
- Pyrrolidines/chemical synthesis
- Pyrrolidines/chemistry
- Pyrrolidines/metabolism
- Pyrrolidines/pharmacology
- Rabbits
- Radioligand Assay
- Receptors, N-Methyl-D-Aspartate/metabolism
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/metabolism
- Stereoisomerism
- Structure-Activity Relationship
Collapse
Affiliation(s)
- S Soukara
- Pharmazeutisches Institut der Universität Freiburg, Hermann-Herder-Strasse 9, 79104 Freiburg i. Br., Germany
| | | | | | | | | | | |
Collapse
|
8
|
Acri JB, Thompson AC, Shippenberg T. Modulation of pre- and postsynaptic dopamine D2 receptor function by the selective kappa-opioid receptor agonist U69593. Synapse 2001; 39:343-50. [PMID: 11169785 DOI: 10.1002/1098-2396(20010315)39:4<343::aid-syn1018>3.0.co;2-q] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The repeated administration of selective kappa-opioid receptor agonists prevents the locomotor activation produced by acute cocaine administration and the development of cocaine-induced behavioral sensitization. Previous studies have shown that dopamine (DA) D2 autoreceptors modulate the synthesis and release of DA in the striatum. Evidence that kappa agonist treatment downregulates DA D2 receptors in this same brain region has recently been obtained. Accordingly, the present studies were undertaken to examine the influence of repeated kappa-opioid receptor agonist administration on pre- and postsynaptic DA D2 receptor function in the dorsal striatum using pre- and postsynaptic receptor-selective doses of quinpirole. Rats were injected once daily with the selective kappa-opioid receptor agonist U69593 (0.16-0.32 mg/kg s.c.) or vehicle for 3 days. Microdialysis studies assessing basal and quinpirole-evoked (0.05 mg/kg s.c.) DA levels were conducted 2 days later. Basal and quinpirole-stimulated locomotor activity were assessed in a parallel group of animals. The no-net flux method of quantitative microdialysis revealed no effect of U69593 on basal DA dynamics, in that extracellular DA concentration and extraction fraction did not differ in control and U69593-treated animals. Acute administration of quinpirole significantly decreased striatal DA levels in control animals, but in animals treated with U69593, the inhibitory effects of quinpirole were significantly reduced. Quinpirole produced a dose-related increase in locomotor activity in control animals, and this effect was significantly attenuated in U69593-treated animals. These data reveal that prior repeated administration of a selective kappa-opioid receptor agonist attenuates quinpirole-induced alterations in DA neurotransmission and locomotor activity. These results suggest that both pre- and postsynaptic striatal DA D2 receptors may be downregulated following repeated kappa-opioid receptor agonist administration. Synapse 39:343-350, 2001. Published 2001 Wiley-Liss, Inc.
Collapse
Affiliation(s)
- J B Acri
- Integrative Neuroscience Unit, Behavioral Neuroscience Branch, NIDA-IRP, 6001 Executive Blvd. Room 4123, MSC 9551, Bethesda, MD 20892-9551, USA.
| | | | | |
Collapse
|
9
|
Izenwasser S, Acri JB, Kunko PM, Shippenberg T. Repeated treatment with the selective kappa opioid agonist U-69593 produces a marked depletion of dopamine D2 receptors. Synapse 1998; 30:275-83. [PMID: 9776131 DOI: 10.1002/(sici)1098-2396(199811)30:3<275::aid-syn5>3.0.co;2-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
U-69593, the selective K-opioid agonist, was repeatedly administered in single daily injections (0.32 mg/kg) to male, Sprague-Dawley rats. Two or ten days later, the rats were euthanized and dopamine D1 and D2 receptors were measured using (3H]SCH 23390 or [3H]sulpiride, respectively, in caudate putamen and nucleus accumbens. Two days after the last of three injections, dopamine D2 receptors in the caudate putamen were decreased by approximately 40%, with no change in D1 receptors. Dopamine D2 receptor number had returned to normal by 10 days posttreatment. In contrast, in the nucleus accumbens there was a small, nonsignificant decrease in dopamine D2 receptors 2 days after treatment, but a large increase (65%) after 10 days. In agreement with the changes in D2 receptors, there was a significant downward shift in the locomotor activity curve for the D2 agonist quinpirole after a 2-day withdrawal. There were no differences in either the total amount of dopamine taken up or in the IC50 for cocaine to inhibit dopamine uptake following this treatment, suggesting that the dopamine transporter and presynaptic terminals were intact. The results of these studies demonstrate that repeated administration of a selective K-opioid agonist induces long-term alterations in dopamine D2 receptors. Furthermore, the finding that these changes in receptor number require both repeated injections and a withdrawal time greater than 1 day suggests that these alterations are compensatory in nature.
Collapse
Affiliation(s)
- S Izenwasser
- Psychobiology Section, National Institute on Drug Abuse, Division of Intramural Research, National Institutes of Health, Baltimore, Maryland, USA.
| | | | | | | |
Collapse
|
10
|
Feuerstein TJ, Seeger W. Modulation of acetylcholine release in human cortical slices: possible implications for Alzheimer's disease. Pharmacol Ther 1997; 74:333-47. [PMID: 9352588 DOI: 10.1016/s0163-7258(97)00006-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Superfused slices of human neocortex, prepared from surgically removed tissue (to gain access to subcortical tumors) and prelabelled with [3H]choline, were stimulated electrically to evoke action potential-induced, exocytotic [3H]acetylcholine release. For comparison, rat cortex slices were also used. [3H]ACh release decreased with the age of the patients and was modulated by muscarinic autoreceptors and by 5-hydroxytryptamine1F, neurokinin1, and kappa-opioid receptors located on cholinergic terminals. In addition, 5-hydroxytryptamine2 and delta-opioid receptors located on interneurons were also involved in the modulation of [3H]ACh release. The present findings might help to explain pathological conditions in Alzheimer's disease.
Collapse
Affiliation(s)
- T J Feuerstein
- Sektion Klinische Neuropharmakologie der Neurologischen Universitätsklinik, Freiburg, Germany
| | | |
Collapse
|
11
|
Ries V, Hertting G, Jackisch R. Properties of 3,4-diaminopyridine-evoked dopamine and acetylcholine release in rabbit caudate nucleus slices: involvement of facilitatory adenosine A2 receptors or nitric oxide? Brain Res 1996; 743:303-14. [PMID: 9017259 DOI: 10.1016/s0006-8993(96)01102-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The 3H-overflow from slices of the rabbit caudate nucleus preincubated with tritiated dopamine (DA), or choline, and then superfused and stimulated twice with 3,4-diaminopyridine (3,4-DAP; 25 microM, 1 min), was explored as an in vitro model for evoked release of DA, or acetylcholine (ACh), respectively. In both cases the 3,4-DAP-evoked 3H-overflow was tetrodotoxin-sensitive and Ca(2+)-dependent and hence most probably represents action potential-induced exocytotic release of DA or ACh, respectively. Using pairs of preferential agonists/antagonists it was shown, that evoked DA release was inhibited via presynaptic D2 autoreceptors (quinpirole/domperidone) and kappa-opioid receptors (U-50488H/norbinaltorphimine). No evidence was found for the presence of presynaptic adenosine A1 or A2 receptors on dopaminergic terminals. Moreover, 3,4-DAP-evoked DA release was unaffected by increased intracellular cyclic AMP levels or by drugs affecting the NO/guanylate cyclase pathway. In a similar manner it was shown that 3,4-DAP-evoked ACh release was inhibited via presynaptic muscarine autoreceptors (oxotremorine/atropine) and dopamine D2 heteroreceptors (quinpirole/domperidone). Again, no evidence for the involvement of the NO/guanylate cyclase system in the modulation of ACh release was found, whereas the presence of inhibitory adenosine A1 receptors, but not of facilitatory A2 receptors, could be clearly established. It is concluded, that 3,4-DAP-evoked 3H-overflow from rabbit caudate nucleus slices preincubated with [3H]DA or [3H]choline, represents a simple and useful in vitro model for action potential-induced DA or ACh release, respectively. Moreover, at least in this model or rabbit brain region, facilitatory adenosine A2 receptors and the NO/guanylate cyclase system seem not to be involved in the release of these transmitters.
Collapse
Affiliation(s)
- V Ries
- Institute of Pharmacology, University of Freiburg, Germany
| | | | | |
Collapse
|
12
|
Chao CC, Gekker G, Hu S, Sheng WS, Shark KB, Bu DF, Archer S, Bidlack JM, Peterson PK. kappa opioid receptors in human microglia downregulate human immunodeficiency virus 1 expression. Proc Natl Acad Sci U S A 1996; 93:8051-6. [PMID: 8755601 PMCID: PMC38873 DOI: 10.1073/pnas.93.15.8051] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Microglial cells, the resident macrophages of the brain, play an important role in the neuropathogenesis of human immunodeficiency virus type 1 (HIV-1), and recent studies suggest that opioid peptides regulate the function of macrophages from somatic tissues. We report herein the presence of kappa opioid receptors (KORs) in human fetal microglia and inhibition of HIV-1 expression in acutely infected microglial cell cultures treated with KOR ligands. Using reverse transcriptase-polymerase chain reaction and sequencing analyses, we found that mRNA for the KOR was constitutively expressed in microglia and determined that the nucleotide sequence of the open reading frame was identical to that of the human brain KOR gene. The expression of KOR in microglial cells was confirmed by membrane binding of [3H]U69,593, a kappa-selective ligand, and by indirect immunofluorescence. Treatment of microglial cell cultures with U50,488 or U69,593 resulted in a dose-dependent inhibition of expression of the monocytotropic HIV-1 SF162 strain. This antiviral effect of the kappa ligands was blocked by the specific KOR antagonist, nor-binaltrophimine. These findings suggest that kappa opioid agonists have immunomodulatory activity in the brain, and that these compounds could have potential in the treatment of HIV-1-associated encephalopathy.
Collapse
MESH Headings
- Analgesics/metabolism
- Base Sequence
- Benzeneacetamides
- Brain/physiology
- Cell Membrane/metabolism
- Cells, Cultured
- DNA, Complementary
- Dynorphins/pharmacology
- Fetus
- Fluorescent Antibody Technique, Indirect
- HIV-1/drug effects
- HIV-1/physiology
- Humans
- Kinetics
- Microglia/drug effects
- Microglia/physiology
- Microglia/virology
- Molecular Sequence Data
- Open Reading Frames
- Peptide Fragments/pharmacology
- Phycoerythrin
- Pyrrolidines/metabolism
- Pyrrolidines/pharmacology
- RNA, Messenger/biosynthesis
- RNA, Messenger/chemistry
- Receptors, Opioid, kappa/biosynthesis
- Receptors, Opioid, kappa/chemistry
- Receptors, Opioid, kappa/physiology
- Transcription, Genetic
- Virus Replication/drug effects
Collapse
Affiliation(s)
- C C Chao
- Neuroimmunobiology and Host Defense Laboratory, Minneapolis Medical Research Foundation and University of Minnesota Medical School, 55404, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
You ZB, Herrera-Marschitz M, Nylander I, Goiny M, Kehr J, Ungerstedt U, Terenius L. Effect of morphine on dynorphin B and GABA release in the basal ganglia of rats. Brain Res 1996; 710:241-8. [PMID: 8963665 DOI: 10.1016/0006-8993(95)01402-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In vivo microdialysis was used to study the effects of systemic, as well as intracerebral administration of morphine and naloxone on dynorphin B release in neostriatum and substantia nigra of rats. The release of dopamine (DA), gamma-aminobutyric acid (GABA), glutamate (Glu) and aspartate (Asp) was also investigated. Systemic injection of morphine (1 mg/kg s.c.) induced long-lasting increases in extracellular dynorphin B and GABA levels in the substantia nigra, whereas DA, Glu and Asp levels, measured in the same region, were not significantly affected. No effect on striatal neurotransmitter levels was observed following systemic morphine administration. Local perfusion of the substantia nigra with morphine (100 microM) through the microdialysis probe also increased nigral dynorphin B and GABA levels. Perfusion of the neostriatum with morphine (100 microM) significantly increased GABA and dynorphin B levels in the ipsilateral substantia nigra, but no effect was observed locally. Naloxone blocked the effect of systemic morphine administration on nigral dynorphin B and GABA release, already at a dose of 0.2 mg/kg s.c. Naloxone alone, given either systemically (0.2-4 mg/kg s.c.) or intracerebrally (1-100 microM), did not affect dynorphin B or amino acid levels, either in neostriatum or in substantia nigra. However, naloxone produced a concentration-dependent increase in DA levels. The present results indicate that systemic morphine administration stimulates the release of dynorphin B in the substantia nigra, probably by activating the mu-subtype of opioid receptor, since the effect of morphine on nigral dynorphin B and GABA was antagonized by a low dose of naloxone. The increase in extracellular DA levels produced by high concentrations of naloxone, both in neostriatum and substantia nigra, indicates a disinhibitory effect of this drug on DA release, probably via a non-mu subtype of opioid receptors located on nigro-striatal DA neurones.
Collapse
Affiliation(s)
- Z B You
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | | | | | | | | | | | | |
Collapse
|
14
|
Sershen H, Hashim A, Lajtha A. The effect of ibogaine on Sigma- and NMDA-receptor-mediated release of [3H]dopamine. Brain Res Bull 1996; 40:63-7. [PMID: 8722755 DOI: 10.1016/0361-9230(96)00039-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The indole alkaloid ibogaine has been suggested to have potential for inhibiting dependency on stimulant drugs. Radioligand binding studies have suggested possible multisite actions of ibogaine: affinity at the kappa-opioid, NMDA, and sigma receptors, with effects on dopamine (DA) release. To further investigate the multiplicity of sites of action of ibogaine and the presynaptic regulation of the DA release, the effect of ibogaine on NMDA- and sigma-receptor-mediated efflux of [3H]DA was measured in striatal tissue from C57BL/6By mice. Striatal tissue was incubated in vitro with [3H]DA and the effect on DA release was measured. Both NMDA (25 microM) alone increased the efflux of DA. (+/)-Pentazocine (100 nM) did not inhibit the NMDA-evoked release. MK-801 (5 microM) completely inhibited the NMDA-evoked release and inhibited the (+/-)-pentazocine-evoked release by 49%. Ibogaine (10 microM) itself increased the efflux of DA; at 1 microM it was without effect. Ibogaine (1 microM) inhibited the NMDA-evoked release of DA by 31% and inhibited the (+/-)-pentazocine-evoked release by 48%. In addition, the level of basal release of DA obtained after the NMDA- or (+/)-pentazocine-evoked-release remained higher in the tissue exposed to ibogaine throughout. The results suggest that sigma receptors can regulate the release of DA, along with an action at the NMDA receptor. We previously reported action of ibogaine at the kappa-opioid site. The elevated basal release of DA in the presence of ibogaine after NMDA- or (+/-)-pentazocine-evoked release may reflect the ibogaine-induced removal of the tonically active kappa-opioid system that acts presynaptically to reduce dopamine release. The kappa-opioid system also appears to be inhibitory on both the NMDA and sigma receptors.
Collapse
Affiliation(s)
- H Sershen
- Nathan S. Kline Institute, Orangeburg, NY 10962, USA
| | | | | |
Collapse
|
15
|
Abstract
Behavioural sensitization involves progressive increases in behavioural responses to repeated intermittent administration of drugs of abuse. Behavioural sensitization is observed to the locomotor stimulant, rewarding and discriminative effects of a drug. These are effects which seem to be essential in the initiation, expression and maintenance of a drug-seeking behaviour. Therefore the phenomenon of behavioural sensitization may have important implications for the understanding of addictive processes. Findings given in this review demonstrate the involvement of endogenous opioid systems in the initiation of sensitized responses on the neurochemical level, i.e., within the mesolimbic dopaminergic system, as well as on the behavioural level. Specifically, it is shown that behavioural sensitization to morphine and cocaine is modulated by endogenous kappa-opioid systems.
Collapse
Affiliation(s)
- R Spanagel
- Max-Planck-Institute of Psychiatry, Department of Neuroendocrinology, Munich, Germany
| |
Collapse
|
16
|
Schlösser B, Kudernatsch MB, Sutor B, ten Bruggencate G. Delta, mu and kappa opioid receptor agonists inhibit dopamine overflow in rat neostriatal slices. Neurosci Lett 1995; 191:126-30. [PMID: 7659278 DOI: 10.1016/0304-3940(94)11552-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The actions of opioid receptor agonists on stimulus evoked dopamine overflow in rat neostriatal slices were investigated using fast cyclic voltammetry. Activation of delta and mu receptors reversibly depressed striatal dopamine efflux induced by intrastriatal stimulation. The inhibitory effect of DADLE (D-Ala2, D-Leu5-enkephalin, delta/mu agonist), DPDPE (D-Pen2,5-enkephalin, delta selective) and DALDA (D-Arg2, Lys4-dermorphin-(1,4)-amide, mu selective), respectively, were concentration dependent and could be blocked by application of receptor subtype selective antagonists. At a concentration of 1 microM, the kappa receptor agonist U-50488H inhibited dopamine overflow. This effect could be partially antagonized by kappa receptor selective antagonists. Prior application of virtually ineffective concentrations (< or = 0.1 microM) of the kappa agonist reduced the efficacy of 1 microM U-50488H suggesting a desensitization of the receptor. Since the stimulus induced dopamine overflow in striatal slices can be attributed solely to the release of dopamine from presynaptic terminals, these experiments demonstrate that delta, mu and kappa opioid receptors exert an inhibitory control on striatal dopamine release via a presynaptic mechanism.
Collapse
MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
- Analgesics/pharmacology
- Animals
- Dopamine/metabolism
- Dopamine Uptake Inhibitors/pharmacology
- Electric Stimulation
- Enkephalin, D-Penicillamine (2,5)-
- Enkephalin, Leucine-2-Alanine/pharmacology
- Enkephalins/pharmacology
- In Vitro Techniques
- Male
- Neostriatum/drug effects
- Neostriatum/metabolism
- Nomifensine/pharmacology
- Oligopeptides/pharmacology
- Pyrrolidines/pharmacology
- Rats
- Rats, Wistar
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/antagonists & inhibitors
Collapse
Affiliation(s)
- B Schlösser
- Department of Physiology, University of Munich, Germany
| | | | | | | |
Collapse
|
17
|
Sershen H, Hashim A, Lajtha A. The effect of ibogaine on kappa-opioid- and 5-HT3-induced changes in stimulation-evoked dopamine release in vitro from striatum of C57BL/6By mice. Brain Res Bull 1995; 36:587-91. [PMID: 7757494 DOI: 10.1016/0361-9230(94)00250-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Ibogaine is an indole alkaloid that has been suggested to have potential efficacy for interrupting dependency on stimulant drugs. The kappa-opioid and serotonin 5-HT3 systems may be involved in the action of ibogaine, related to their modulation of dopaminergic transmission. The kappa-opioid agonist U 62066 attenuated the in vitro stimulation-evoked efflux of tritium label from striatal tissue prelabeled with [3H]dopamine. In mice pretreated with ibogaine.HCI (40 mg/kg IP given 2 h prior or 2 x 40 mg/kg and animals killed 18 h later), the inhibitory effect of U 62066 on stimulation-evoked release of tritium was eliminated. The 5-HT3 agonist phenylbiguanide had a biphasic effect on stimulation-evoked release of tritium; at 10(-6) M phenylbiguanide, stimulation-evoked release was attenuated. At 10(-5) M the basal outflow of tritium was increased. Ibogaine pretreatment had no effect on basal or stimulation-evoked release in the presence of 10(-6) M phenylbiguanide, but increased the stimulation-evoked outflow of tritium in the presence of 10(-5) M phenylbiguanide. Cocaine (10(-6) M), a dopamine uptake blocker, increased the electrically-evoked release of dopamine; ibogaine pretreatment did not affect the enhanced electrically-induced release of [3H]dopamine by in vitro cocaine. The effects of ibogaine on the kappa-opioid and 5-HT3 receptors, located presynaptically on striatal dopamine terminals, modulating dopamine release may partly underlie its putative antiaddictive properties.
Collapse
Affiliation(s)
- H Sershen
- Nathan S. Kline Institute, Center for Neurochemistry, Orangeburg, NY 10962, USA
| | | | | |
Collapse
|
18
|
Spanagel R, Shoaib M. Involvement of mesolimbic kappa-opioid systems in the discriminative stimulus effects of morphine. Neuroscience 1994; 63:797-804. [PMID: 7898679 DOI: 10.1016/0306-4522(94)90524-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The neuroanatomical basis of opiate addiction has been studied using a variety of behavioural techniques. The aim of the present study was to investigate the role of mesolimbic opioid systems, in particular kappa-opioid systems, in the expression of the discriminative stimulus effects of abused drugs. Rats were trained to discriminate morphine (3.0 mg/kg s.c.) from saline under a fixed ratio schedule of food reinforcement. Once rats had acquired the discrimination, a randomized sequence of different doses of the highly selective kappa-opioid receptor agonist U69593 (0.02-0.16 mg/kg s.c.) was given 20 min prior to a systemic morphine injection. U69593 dose-dependently blocked the morphine discrimination. It is important to note that U69593 at these doses failed to generalize to the systemic morphine cue. The site of action by U69593 (0.02-0.16 microgram) was examined by microinjecting discrete amounts into target brain regions. Intra-nucleus accumbens injections of U69593 dose-dependently blocked the systemic morphine cue, whereas, U69593 failed to generalize to the discriminative stimulus. The same doses did not affect morphine discrimination after intra-ventral tegmental area or striatum injections. Besides the rewarding effects of drugs of abuse, the discriminative stimulus properties of these agents are seen as a major factor in drug seeking behaviours. The present study shows that the discriminative effects of morphine, a measure of the subjective effects of this drug can be blocked by the activation of kappa-opioid receptors located in the nucleus accumbens. In view of these findings which show that the activity of endogenous potassium-opioid systems (dynorphin) may serve as physiological antagonists to counteract the effects of morphine, potassium-agonists therefore may be useful in the treatment of opioid addictions.
Collapse
Affiliation(s)
- R Spanagel
- Department of Neuroendocrinology, Max Planck Institute of Psychiatry, Clinical Institute, Munich, Germany
| | | |
Collapse
|
19
|
Spanagel R, Almeida OF, Bartl C, Shippenberg TS. Endogenous kappa-opioid systems in opiate withdrawal: role in aversion and accompanying changes in mesolimbic dopamine release. Psychopharmacology (Berl) 1994; 115:121-7. [PMID: 7862883 DOI: 10.1007/bf02244761] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The kappa-opioid receptor antagonist nor-binaltorphimine (nor-BNI) was recently shown to potentiate certain overt withdrawal signs in morphine-dependent rats. The present study sought to further assess this phenomenon by examining the influence of nor-BNI treatment upon the conditioned place aversion associated with the naloxone-precipitated withdrawal syndrome. In addition, in vivo microdialysis studies were conducted in morphine-dependent rats to determine whether nor-BNI treatment can modify withdrawal-induced changes in basal dopamine (DA) release within the mesolimbic system. Rats were pretreated with either saline or a single dose of nor-BNI and then received ascending doses of morphine for 10 days. A withdrawal syndrome was then precipitated by the administration of naloxone (1 mg/kg SC). In rats which received chronic morphine injections, administration of naloxone produced a characteristic withdrawal syndrome and a marked aversion for an environment previously associated with naloxone-precipitated withdrawal. Nor-BNI treatment potentiated most overt signs of physical dependence. This treatment also resulted in a greater withdrawal-induced place aversion. Morphine-dependent rats exhibited a marked reduction in basal mesolimbic DA release. An even greater decrease in basal DA release was observed in nor-BNI treated rats. These results suggest that endogenous kappa-systems are important in the modulation of mesolimbic DA release and the accompanying place aversion which occurs during opiate withdrawal.
Collapse
Affiliation(s)
- R Spanagel
- Department of Neuroendocrinology, Max-Planck-Institute of Psychiatry, Munich, Germany
| | | | | | | |
Collapse
|