{"title":"Conorphin-66 produces peripherally restricted antinociception via the kappa-opioid receptor with limited side effects","authors":"","doi":"10.1016/j.neuropharm.2024.110157","DOIUrl":null,"url":null,"abstract":"<div><p>With the current unmet demand for effective pain relief, analgesics without major central adverse effects are highly appealing, such as peripherally restricted kappa-opioid receptor (KOR) agonists. In this study, Conorphin-66, an analog of the selective KOR peptide agonist Conorphin T, was pharmacologically characterized in a series of experiments, with CR845 serving as the reference compound. Firstly, <em>in vitro</em> functional assay indicated that Conorphin-66 selectively activates KOR and exhibits weak β-arrestin2 signaling bias (−1.54 versus −4.35 for CR845). Additionally, subcutaneous Conorphin-66 produced potent antinociception in mouse pain models with ED<sub>50</sub> values ranged from 0.02 to 3.28 μmol/kg, including tail-flick test, post-operative pain, formalin pain, and acetic acid-induced visceral pain. Similarly, CR845 exert potent antinociception in mouse pain models ranged from 0.15 to 1.47 μmol/kg. Notably, antagonism studies revealed that the analgesic effects of Conorphin-66 were mainly mediated by the peripheral KOR. Furthermore, Conorphin-66 produced non-tolerance-forming antinociception over 8 days. Unlike CR845, subcutaneous Conorphin-66 did not promote the sedation, anxiogenic effects, depressive-like effects, but did exhibit diuretic activity. Further study showed that Conorphin-66 does not have apparent antipruritic effects in an acute itch model. Overall, Conorphin-66 emerges as a novel peripherally restricted KOR agonist that produced potent antinociception with reduced side effects.</p></div>","PeriodicalId":19139,"journal":{"name":"Neuropharmacology","volume":null,"pages":null},"PeriodicalIF":4.6000,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Neuropharmacology","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0028390824003265","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"NEUROSCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
With the current unmet demand for effective pain relief, analgesics without major central adverse effects are highly appealing, such as peripherally restricted kappa-opioid receptor (KOR) agonists. In this study, Conorphin-66, an analog of the selective KOR peptide agonist Conorphin T, was pharmacologically characterized in a series of experiments, with CR845 serving as the reference compound. Firstly, in vitro functional assay indicated that Conorphin-66 selectively activates KOR and exhibits weak β-arrestin2 signaling bias (−1.54 versus −4.35 for CR845). Additionally, subcutaneous Conorphin-66 produced potent antinociception in mouse pain models with ED50 values ranged from 0.02 to 3.28 μmol/kg, including tail-flick test, post-operative pain, formalin pain, and acetic acid-induced visceral pain. Similarly, CR845 exert potent antinociception in mouse pain models ranged from 0.15 to 1.47 μmol/kg. Notably, antagonism studies revealed that the analgesic effects of Conorphin-66 were mainly mediated by the peripheral KOR. Furthermore, Conorphin-66 produced non-tolerance-forming antinociception over 8 days. Unlike CR845, subcutaneous Conorphin-66 did not promote the sedation, anxiogenic effects, depressive-like effects, but did exhibit diuretic activity. Further study showed that Conorphin-66 does not have apparent antipruritic effects in an acute itch model. Overall, Conorphin-66 emerges as a novel peripherally restricted KOR agonist that produced potent antinociception with reduced side effects.
期刊介绍:
Neuropharmacology publishes high quality, original research and review articles within the discipline of neuroscience, especially articles with a neuropharmacological component. However, papers within any area of neuroscience will be considered. The journal does not usually accept clinical research, although preclinical neuropharmacological studies in humans may be considered. The journal only considers submissions in which the chemical structures and compositions of experimental agents are readily available in the literature or disclosed by the authors in the submitted manuscript. Only in exceptional circumstances will natural products be considered, and then only if the preparation is well defined by scientific means. Neuropharmacology publishes articles of any length (original research and reviews).