ArticlePloS one2016
Efficacy of Intrathecal Morphine in a Model of Surgical Pain in Rats.
Article in PloS one, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers, 1 of them a synthesis that pooled it.
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Who cites it
12 citing papers in PubMed, 1 synthesis or guideline pooled it, 24 citations in OpenAlex.
- Grimace scale, burrowing, and nest building for the assessment of post-surgical pain in mice and rats-A systematic review.Frontiers in veterinary science · 2022Pooled it
- Oscillatory activity and LFP power modulation in the hippocampal CA1 and prelimbic cortex during morphine-induced place preference.IBRO neuroscience reports · 2026Article
- [Orexin-A promotes motor function recovery of rats with spinal cord injury by regulating ionotropic glutamate receptors].Nan fang yi ke da xue xue bao = Journal of Southern Medical University · 2025Article
- Liquiritin ameliorates painful diabetic neuropathy in SD rats by inhibiting NLRP3-MMP-9-mediated reversal of aquaporin-4 polarity in the glymphatic system.Frontiers in pharmacology · 2024Article
- Intrathecal Administration of Nanoclusters for Protecting Neurons against Oxidative Stress in Cerebral Ischemia/Reperfusion Injury.ACS nano · 2019Article
- Evans Blue Reduces Neuropathic Pain Behavior by Inhibiting Spinal ATP Release.International journal of molecular sciences · 2019Article
- Characterization of Cancer-Induced Nociception in a Murine Model of Breast Carcinoma.Cellular and molecular neurobiology · 2019Article
- Neuronal and glial factors contributing to sex differences in opioid modulation of pain.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2019Review
- Sciatic nerve injury following analgesic drug injection in rats: A histopathological examination.Northern clinics of Istanbul · 2018Article
- Article
- Article
- Effects of Intraperitoneal and Intrathecal Morphine Analgesia on the Expression of μ-Opioid Receptors in Bone Cancer Pain Rats.Dose-response : a publication of International Hormesis SocietyArticle
Corrections and comments
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Authors and funding
8 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Concerns over interactions between analgesics and experimental outcomes are a major reason for withholding opioids from rats undergoing surgical procedures. Only a fraction of morphine injected intravenously reaches receptors responsible for analgesia in the central nervous system. Intrathecal administration of morphine may represent a way to provide rats with analgesia while minimizing the amount of morphine injected. This study aimed to assess whether morphine injected intrathecally via direct lumbar puncture provides sufficient analgesia to rats exposed to acute surgical pain (caudal laparotomy).In an initial blinded, randomised study, pain-free rats received morphine subcutaneously (MSC, 3mg.kg-1, N = 6), intrathecally (MIT, 0.2mg.kg-1, N = 6); NaCl subcutaneously (NSC, N = 6) or intrathecally (NIT, N = 6). Previously validated pain behaviours, activity and Rat Grimace Scale (RGS) scores were recorded at baseline, 1, 2, 4 and 8h post-injection. Morphine-treated rats had similar behaviours to NaCl rats, but their RGS scores were significantly different over time and between treatments. In a second blinded study, rats (N = 28) were randomly allocated to one of the following four treatments (N = 7): MSC, 3mg.kg-1, surgery; MIT, 0.2mg.kg-1, surgery; NIT, surgery; NSC, sham surgery. Composite Pain Behaviours (CPB) and RGS were recorded as previously. CPB in MIT and MSC groups were not significantly different to NSC group. MSC and MIT rats displayed significantly lower RGS scores than NIT rats at 1 and 8h postoperatively. RGS scores for MIT and MSC rats were not significantly different at 1, 2, and 8h postoperatively. Intraclass correlation value amongst operators involved in RGS scoring (N = 9) was 0.913 for total RGS score. Intrathecal morphine was mostly indistinguishable from its subcutaneous counterpart, providing pain relief lasting up to 8 hours in a rat model of surgical pain. Further studies are warranted to clarify the relevance of the rat grimace scale for assessing pain in rats that have received opioid analgesics.
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