ArticlePsychopharmacology2007
Sex differences in the potency of kappa opioids and mixed-action opioids administered systemically and at the site of inflammation against capsaicin-induced hyperalgesia in rats.
Article in Psychopharmacology, 2007. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
16 citing papers in PubMed, 28 citations in OpenAlex.
- Optogenetic stimulation of pyramidal neurons in the rat primary visual cortex modulates ON- and OFF- receptive field areas independently.Scientific reports · 2025Article
- Local stimulation of pyramidal neurons in deep cortical layers of anesthetized rats enhances cortical visual information processing.Scientific reports · 2024Article
- An efficient rAAV vector for protein expression in cortical parvalbumin expressing interneurons.Scientific reports · 2022Article
- Article
- Sex differences in kappa opioid receptor inhibition of latent postoperative pain sensitization in dorsal horn.Neuropharmacology · 2020Article
- Analgesic Effect Comparison Between Nalbuphine and Sufentanil for Patient-Controlled Intravenous Analgesia After Cesarean Section.Frontiers in pharmacology · 2020Article
- Core Outcome Measures in Preclinical Assessment of Candidate Analgesics.Pharmacological reviews · 2019Review
- Experimentally derived model shows that adaptation acts as a powerful spatiotemporal filter of visual responses in the rat collicular neurons.Scientific reports · 2018Article
- Gender differences in acute and chronic pain in the emergency department: results of the 2014 Academic Emergency Medicine consensus conference pain section.Academic emergency medicine : official journal of the Society for Academic Emergency Medicine · 2014Article
- Peripheral sensitization increases opioid receptor expression and activation by crotalphine in rats.PloS one · 2014Article
- Sex differences in opioid analgesia and addiction: interactions among opioid receptors and estrogen receptors.Molecular pain · 2013Review
- Effects of peripheral κ opioid receptor activation on inflammatory mechanical hyperalgesia in male and female rats.Neuroscience letters · 2012Article
- Opioid system and Alzheimer's disease.Neuromolecular medicine · 2012Review
- Sex differences in kappa opioid pharmacology.Life sciences · 2011Review
- Antinociceptive interactions between Mu-opioid receptor agonists and the serotonin uptake inhibitor clomipramine in rhesus monkeys: role of Mu agonist efficacy.The Journal of pharmacology and experimental therapeutics · 2010Article
- Sex, gender, and pain: an overview of a complex field.Anesthesia and analgesia · 2008Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 1 institution in 1 country.
Funding
Abstract
rationaleSex differences in the potency of the antinociceptive effects of kappa opioids have been reported in various acute pain models with evidence suggesting that these sex differences are mediated by activity in the N-methyl-D: -aspartate (NMDA) system.
objectivesThe purpose of the present study was to evaluate sex differences in the antihyperalgesic actions of selected kappa and mixed-action opioids in a persistent pain model and determine if the NMDA system modulates these effects in a sexually dimorphic manner.
methodsUsing gonadally intact male and female F344 rats, hyperalgesia was induced by local administration of capsaicin in the tail, after which the tail was immersed in a mildly noxious thermal stimulus (45 degrees C water), and tail-withdrawal latency measured. Opioids were then administered systemically (s.c.) and locally (in the tail) alone, and in selected combinations with the noncompetitive NMDA antagonist dextromethorphan.
resultsWhen administered systemically and locally, the kappa opioids spiradoline, U69,593 and U50,488, and the mixed-action opioids butorphanol and nalbuphine, produced dose-dependent antihyperalgesic effects. Whereas the kappa opioids were generally more potent in males, sex differences were not observed with the mixed-action opioids. Peripheral receptor activity was confirmed for local administration of kappa opioids by the antagonism observed after local, but not intracerebroventricular (i.c.v.), administration of the kappa antagonist nor-binaltorphamine (nor-BNI). Dextromethorphan was equally potent in attenuating the antihyperalgesia induced by kappa opioids in both males and females.
conclusionsThese findings demonstrate sex differences in kappa opioid activity in a persistent pain model. Although an NMDA antagonist blocked the effects of kappa opioids in this model, these effects were not sexually dimorphic as reported in most acute pain models.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.