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Santos EJ, Akbarali HI, Bow EW, Chambers DR, Gutman ES, Jacobson AE, Kang M, Lee YK, Lutz JA, Rice KC, Sulima A, Negus SS. Low-Efficacy Mu Opioid Agonists as Candidate Analgesics: Effects of Novel C-9 Substituted Phenylmorphans on Pain-Depressed Behavior in Mice. J Pharmacol Exp Ther 2024:JPET-AR-2024-002153. [PMID: 38637015 DOI: 10.1124/jpet.124.002153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/11/2024] [Accepted: 03/27/2024] [Indexed: 04/20/2024] Open
Abstract
Low efficacy mu opioid receptor (MOR) agonists may serve as novel candidate analgesics with improved safety relative to high-efficacy opioids. This study used a recently validated assay of pain-depressed behavior in mice to evaluate a novel series of MOR-selective C9-substituted phenylmorphan opioids with graded MOR efficacies. Intraperitoneal injection of dilute lactic acid (IP acid) served as a noxious stimulus to depress locomotor activity by mice in an activity chamber composed of two compartments connected by an obstructed door. Behavioral measures included (1) crosses between compartments (vertical activity over the obstruction) and (2) movement counts quantified as photobeam breaks summed across compartments (horizontal activity). Each drug was tested alone and as a pretreatment to IP acid. A charcoal-meal test and whole-body-plethysmography assessment of breathing in 5% CO2 were also used to assess gastrointestinal (GI) inhibition and respiratory depression, respectively. IP acid produced a concentration-dependent depression in crosses and movement that was optimally alleviated by intermediate- to low-efficacy phenylmorphans with sufficient efficacy to produce analgesia with minimal locomotor disruption. Follow-up studies with two low-efficacy phenylmorphans (JL-2-39 and DC-1-76.1) indicated that both drugs produced naltrexone-reversible antinociception with a rapid onset and a duration of ~1hr. Potency of both drugs increased when behavior was depressed by a lower IP-acid concentration, and neither drug alleviated behavioral depression by a non-pain stimulus (IP lithium chloride). Both drugs produced weaker GI inhibition and respiratory depression than fentanyl and attenuated fentanyl-induced GI inhibition and respiratory depression. Results support further consideration of selective, low-efficacy MOR agonists as candidate analgesics. Significance Statement This study used a novel set of mu opioid receptor (MOR)-selective opioids with graded MOR efficacies to examine the lower boundary of MOR efficacy sufficient to relieve pain-related behavioral depression in mice. Two novel low-efficacy opioids (JL-2-39, DC-1-76.1) produced effective antinociception with improved safety relative to higher- or lower-efficacy opioids, and results support further consideration of these and other low-efficacy opioids as candidate analgesics.
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Affiliation(s)
- Edna J Santos
- Pharmacology & Toxicology, Virginia Commonwealth University, United States
| | - Hamid I Akbarali
- Pharmacology and Toxicology, Virginia Commonwealth University, United States
| | | | | | | | | | - Minho Kang
- Pharm & Tox, Virginia Commonwealth University, United States
| | - Young K Lee
- Pharmacology and Toxicology, Virginia Commonwealth University, United States
| | | | | | - Agnieszka Sulima
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, NIDA and NIAAA, United States
| | - S Stevens Negus
- Pharmacology and Toxicology, Virginia Commonwealth University, United States
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Santos EJ, Nassehi N, Bow EW, Chambers DR, Gutman ES, Jacobson AE, Lutz JA, Marsh SA, Rice KC, Sulima A, Selley DE, Negus SS. Role of efficacy as a determinant of locomotor activation by mu-opioid receptor (MOR) ligands in female and male mice. II. Effects of novel MOR-selective phenylmorphans with high-to-low MOR efficacy. Pharmacol Res Perspect 2023; 11:e01111. [PMID: 37381112 DOI: 10.1002/prp2.1111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 06/05/2023] [Indexed: 06/30/2023] Open
Abstract
Low-efficacy mu-opioid receptor (MOR) agonists represent promising therapeutics, but existing compounds (e.g., buprenorphine, nalbuphine) span a limited range of low MOR efficacies and have poor MOR selectivity. Accordingly, new and selective low-efficacy MOR agonists are of interest. A novel set of chiral C9-substituted phenylmorphans has been reported to display improved MOR selectivity and a range of high-to-low MOR efficacies under other conditions; however, a full opioid receptor binding profile for these drugs has not been described. Additionally, studies in mice will be useful for preclinical characterization of these novel compounds, but the pharmacology of these drugs in mice has also not been examined. Accordingly, the present study characterized the binding selectivity and in vitro efficacy of these compounds using assays of opioid receptor binding and ligand-stimulated [35 S]GTPɣS binding. Additionally, locomotor effects were evaluated as a first step for in vivo behavioral assessment in mice. The high-efficacy MOR agonist and clinically effective antidepressant tianeptine was included as a comparator. In binding studies, all phenylmorphans showed improved MOR selectivity relative to existing lower-efficacy MOR agonists. In the ligand-stimulated [35 S]GTPɣS binding assay, seven phenylmorphans had graded levels of sub-buprenorphine MOR efficacy. In locomotor studies, the compounds again showed graded efficacy with a rapid onset and ≥1 h duration of effects, evidence for MOR mediation, and minor sex differences. Tianeptine functioned as a high-efficacy MOR agonist. Overall, these in vitro and in vivo studies support the characterization of these compounds as MOR-selective ligands with graded MOR efficacy and utility for further behavioral studies in mice.
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Affiliation(s)
- Edna J Santos
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Nima Nassehi
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Eric W Bow
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, NIDA and NIAAA, Bethesda, Maryland, USA
| | - Dana R Chambers
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, NIDA and NIAAA, Bethesda, Maryland, USA
| | - Eugene S Gutman
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, NIDA and NIAAA, Bethesda, Maryland, USA
| | - Arthur E Jacobson
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, NIDA and NIAAA, Bethesda, Maryland, USA
| | - Joshua A Lutz
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, NIDA and NIAAA, Bethesda, Maryland, USA
| | - Samuel A Marsh
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Kenner C Rice
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, NIDA and NIAAA, Bethesda, Maryland, USA
| | - Agnieszka Sulima
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, NIDA and NIAAA, Bethesda, Maryland, USA
| | - Dana E Selley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - S Stevens Negus
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
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Lutz JA, Sulima A, Gutman ES, Bow EW, Luo D, Kaska S, Prisinzano TE, Paronis CA, Bergman J, Imler GH, Kerr AT, Jacobson AE, Rice KC. Discovery of a Potent Highly Biased MOR Partial Agonist among Diastereomeric C9-Hydroxyalkyl-5-phenylmorphans. Molecules 2023; 28:4795. [PMID: 37375350 DOI: 10.3390/molecules28124795] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 05/30/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
All possible diastereomeric C9-hydroxymethyl-, hydroxyethyl-, and hydroxypropyl-substituted 5-phenylmorphans were synthesized to explore the three-dimensional space around the C9 substituent in our search for potent MOR partial agonists. These compounds were designed to lessen the lipophilicity observed with their C9-alkenyl substituted relatives. Many of the 12 diastereomers that were obtained were found to have nanomolar or subnanomolar potency in the forskolin-induced cAMP accumulation assay. Almost all these potent compounds were fully efficacious, and three of those chosen for in vivo evaluation, 15, 21, and 36, were all extremely G-protein biased; none of the three compounds recruited beta-arrestin2. Only one of the 12 diastereomers, 21 (3-((1S,5R,9R)-9-(2-hydroxyethyl)-2-phenethyl-2-azabicyclo[3.3.1]nonan-5-yl)phenol), was a MOR partial agonist with good, but not full, efficacy (Emax = 85%) and subnanomolar potency (EC50 = 0.91 nM) in the cAMP assay. It did not have any KOR agonist activity. This compound was unlike morphine in that it had a limited ventilatory effect in vivo. The activity of 21 could be related to one or more of three well-known theories that attempt to predict a dissociation of the desired analgesia from the undesirable opioid-like side-effects associated with clinically used opioids. In accordance with the theories, 21 was a potent MOR partial agonist, it was highly G-protein biased and did not attract beta-arrestin2, and it was found to have both MOR and DOR agonist activity. All the other diastereomers that were synthesized were either much less potent than 21 or had either too little or too much efficacy for our purposes. It was also noted that a C9-methoxymethyl compound with 1R,5S,9R stereochemistry (41) was more potent than the comparable C9-hydroxymethyl compound 11 (EC50 = 0.65 nM for 41 vs. 2.05 nM for 11). Both 41 and 11 were fully efficacious.
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Affiliation(s)
- Joshua A Lutz
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, USA
| | - Agnieszka Sulima
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, USA
| | - Eugene S Gutman
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, USA
| | - Eric W Bow
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, USA
| | - Dan Luo
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 S. Limestone Street, Lexington, KY 40536, USA
| | - Sophia Kaska
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 S. Limestone Street, Lexington, KY 40536, USA
| | - Thomas E Prisinzano
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 S. Limestone Street, Lexington, KY 40536, USA
| | - Carol A Paronis
- McLean Hospital/Harvard Medical School, 115 Mill Street, Belmont, MA 02478, USA
| | - Jack Bergman
- McLean Hospital/Harvard Medical School, 115 Mill Street, Belmont, MA 02478, USA
| | - Gregory H Imler
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375-0001, USA
| | - Andrew T Kerr
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375-0001, USA
| | - Arthur E Jacobson
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, USA
| | - Kenner C Rice
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, 9800 Medical Center Drive, Bethesda, MD 20892-3373, USA
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Affiliation(s)
- Joshua A. Lutz
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70810, United States
| | - Carol M. Taylor
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70810, United States
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Abstract
The acid-mediated condensation of acetamide with butanal dimethylacetal and EtSCH2CH(OMe)2, followed by dehydration, was investigated by electronic structure calculations that supported the prediction that the Z-geometry would be favored in the product. The reaction was investigated experimentally using suitably functionalized cysteine building blocks. Some side reactions and optimization of reaction conditions are reported, en route to identifying a mild, inexpensive Lewis acid that achieves a reasonable yield of (Z)-thioenamide 21 with high stereoselectivity.
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Affiliation(s)
- Joshua A Lutz
- Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - Visal Subasinghege Don
- Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - Revati Kumar
- Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - Carol M Taylor
- Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States
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Wagner M, Gloor B, Ambühl M, Worni M, Lutz JA, Angst E, Candinas D. Roux-en-Y drainage of the pancreatic stump decreases pancreatic fistula after distal pancreatic resection. J Gastrointest Surg 2007; 11:303-8. [PMID: 17458602 DOI: 10.1007/s11605-007-0094-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Clinically relevant fistula after distal pancreatic resection occurs in 5-30% of patients, prolonging recovery and considerably increasing in-hospital stay and costs. We tested whether routine drainage of the pancreatic stump into a Roux-en-Y limb after distal pancreatic resection decreased the incidence of fistula. From October 2001, data of all patients undergoing pancreatic distal resection were entered in a prospective database. From June 2003 after resection, the main pancreatic duct and the pancreatic stump were oversewn, and in addition, anastomosed into a jejunal Roux-en-Y limb by a single-layer suture (n = 23). A drain was placed near the anastomosis, and all patients received octreotide for 5-7 days postoperatively. The volume of the drained fluid was registered daily, and concentration of amylase was measured and recorded every other day. Patient demographics, hospital stay, pancreatic fistula incidence (> or =30 ml amylase-rich fluid/day on/after postoperative day 10), perioperative morbidity, and follow-up after discharge were compared with our initial series of patients (treated October 2001-May 2003) who underwent oversewing only (n = 20). Indications, patient demographics, blood loss, and tolerance of an oral diet were similar. There were four (20%) pancreatic fistulas in the "oversewn" group and none in the anastomosis group (p < 0.05). Nonsurgical morbidity, in-hospital stay, and follow-up were comparable in both groups.
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Affiliation(s)
- M Wagner
- Department of Visceral and Transplantation Surgery, Inselspital, University of Bern, Murtenstr., CH-3010, Bern, Switzerland
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