We hypothesized that the up-regulated expression of one or more members of the regulator of G protein signaling (RGS) family can cause an attenuation of signaling via Gi/Go-coupled opioid receptors, and thereby play a role in the development of hyperalgesia and accompanying insensitivity to morphine observed in animal models of neuropathic pain. Accordingly, we examined the mRNA expression of several RGS genes in a rat model of chronic neuropathic pain induced by partial ligation of the sciatic nerve. During the development of hyperalgesia, RGS4 was the only isoform examined whose mRNA levels increased significantly (up to 230%) in the lumbar spinal cord. In situ hybridization studies confirmed that RGS4 is present in the dorsal horn of the spinal cord where mu-opioid receptors (MORs) are also expressed. Overexpression of RGS4 in human embryonic kidney 293 cells stably expressing mu-opioid receptors predictably attenuated opioid agonist-induced inhibition of adenylyl cyclase. This inhibitory effect was overcome partially at high agonist concentrations, supporting the view that morphine insensitivity is promoted by RGS4 overexpression. These studies provide evidence that the up-regulation of RGS4 expression may contribute to changes in pain signal processing that lead to the development of hyperalgesia, and further affect its modulation by morphine.
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http://dx.doi.org/10.1124/jpet.102.043471 | DOI Listing |
BMC Anesthesiol
January 2025
Department of Anaesthesia and Intensive Care, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Background: Postoperative pain remains a significant problem in patients undergoing donor nephrectomy despite reduced tissue trauma following laparoscopic living donor nephrectomy (LLDN). Inadequately treated pain leads to physiological and psychological consequences, including chronic neuropathic pain.
Materials And Methods: This randomized controlled double-blinded trial was conducted in sixty-nine (n = 69) participants who underwent LLDN under general anesthesia.
BMC Neurol
January 2025
General Physician, Arab Care Hospital, Ramallah, 00970, Palestine.
Background: Trigeminal neuralgia (TN) is a prevalent and debilitating craniofacial pain disorder characterized by severe, unilateral, shock-like pain. Standard treatments include anti-epileptic drugs and surgical interventions, but many patients experience limited relief or adverse effects. Non-invasive therapies, such as transcutaneous electrical nerve stimulation (TENS), have emerged as alternative options.
View Article and Find Full Text PDFReg Anesth Pain Med
January 2025
Department of Pharmacology, College of Medicine, The Catholic University of Korea, Seoul, South Korea
Introduction: Postherpetic neuralgia (PHN) is a common complication of herpes zoster (HZ). This study aimed to use a large real-world electronic medical records database to determine the optimal machine learning model for predicting the progression to severe PHN and to identify the associated risk factors.
Methods: We analyzed the electronic medical records of 23,326 patients diagnosed with HZ from January 2010 to June 2020.
Pharmacol Res
January 2025
University Hospital of Jena, Institute of Physiology 1, D-07740 Jena, Germany. Electronic address:
Musculoskeletal pain has a high prevalence of transition to chronic pain and/or persistence as chronic pain for years or even a lifetime. Possible mechanisms for the development of such pain states are often reflected in inflammatory or neuropathic processes involving, among others, cytokines and other molecules. Since biologics such as blockers of TNF or IL-6 can attenuate inflammation and pain in a subset of patients with rheumatoid arthritis, the question arises to what extent cytokines are involved in the generation of pain in human musculoskeletal diseases.
View Article and Find Full Text PDFPharmacoepidemiol Drug Saf
January 2025
Department of Clinical Epidemiology & Health Economics, School of Public Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Purpose: To assess adverse neurological risks following influenza vaccination in older adults.
Methods: Using a linked database of healthcare administrative claims data and vaccination records from an urban city in Japan (April 1, 2014, to March 31, 2020), we conducted an observational study utilizing a self-controlled case series design. We identified individuals aged ≥ 65 years who experienced adverse neurological outcomes, defined as hospitalizations related to epilepsy, paralysis, facial paralysis, neuralgia, neuritis, optic neuritis, migraine, extrapyramidal disorders, Guillain-Barre syndrome, or narcolepsy.
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