Background & Aims: Although inflammatory and immune cells are present in the gut in the absence of pathology, their presence does not result in sensitization of sensory nerves, implying the existence of a local antinociceptive influence. We hypothesized that a component of the immune system exerts an antinociceptive influence, thus enabling the gut to function in the absence of undue pain or discomfort.
Methods: Visceromotor responses to colorectal distention were measured in mice with severe combined immune deficiency (SCID) and their wild-type controls.
Results: SCID mice exhibited significantly lower pain thresholds. Transfer of CD4(+) T, but not B lymphocytes, normalized visceral pain in these mice. The restoration of normal visceral nociception following T-cell reconstitution in SCID mice was blocked by naloxone methiodide. Using an enzyme immunoassay and immunohistochemistry for beta-endorphin, we showed that in vitro stimulation of T lymphocytes induced the synthesis and release of beta-endorphin and that transfer of T cells into SCID mice increased the expression of beta-endorphin in the enteric nervous system.
Conclusions: These findings indicate that the immune system is a critical determinant of visceral nociception and that T lymphocytes provide an important opioid-mediated antinociceptive influence in the gut.
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http://dx.doi.org/10.1053/j.gastro.2006.01.045 | DOI Listing |
BMC Gastroenterol
January 2025
Department of Anesthesiology, First Affiliated Hospital, Fujian Medical University, No. 20, Cha Zhong Road, Fuzhou, Fujian Province, People's Republic of China.
Background: Visceral pain sensitization and emotional reactions due to irritable bowel syndrome (IBS) occur frequently in the general population. Oxidative stress plays a crucial role in the pathogenesis of IBS. Previous studies have demonstrated that activation of peroxisome proliferator-activated receptor gamma (PPARγ) has analgesic effects.
View Article and Find Full Text PDFEur J Neurosci
January 2025
Laboratory of Cortico-Visceral Physiology, Pavlov Institute of Physiology of the Russian Academy of Sciences, Saint Petersburg, Russia.
The serotonergic raphe magnus (RMg) and dorsal raphe (DR) nuclei are crucial pain-regulating structures, which nociceptive activity is shown to be altered in gut pathology, but the underlying neuroplastic changes remain unclear. Considering the importance of 5-HT1A receptors in modulating both pain and raphe neuronal activity, in this study, we aimed to determine whether 5-HT1A-dependent visceral and somatic nociceptive processing within the RMg and DR is modified in postcolitis conditions. In anaesthetised male Wistar rats, healthy control and recovered from TNBS-induced colitis, the microelectrode recordings of RMg and DR neuron responses to noxious colorectal distension (CRD) or tail squeezing (TS) were performed prior and after intravenous administration of 5-HT1A agonist, buspirone.
View Article and Find Full Text PDFCell Signal
January 2025
Department of Anesthesia, Jiaxing University Affiliated Women and Children Hospital, Jiaxing 314050, Zhejiang Province, PR China. Electronic address:
Background: While TRPA1 serves as a therapeutic target for nociceptive pain, its role in acute visceral pain induced by uterine cervical dilation (UCD) remains an enigma. This study aims to elucidate the upstream and downstream mechanisms of TRPA1 in the context of UCD-induced acute visceral pain.
Methods: The UCD rats were administered with SAH (inhibitor of the METTL3-METTL14 complex) via intrathecal tubing.
Global Spine J
January 2025
Department of Neurosurgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Study Design: Systematic Review.
Objectives: Formalized terminology for pain experienced by spine cancer patients is lacking. The common descriptors of spine cancer pain as mechanical or non-mechanical is not exhaustive.
Paediatr Drugs
January 2025
Department of Neonatal and Pediatric Intensive Care, Division of Neonatology, Erasmus MC - Sophia Children's Hospital, Rotterdam, The Netherlands.
Necrotizing enterocolitis (NEC) is a relatively rare but very severe gastrointestinal disease primarily affecting very preterm infants. NEC is characterized by excessive inflammation and ischemia in the intestines, and is associated with prolonged, severe visceral pain. Despite its recognition as a highly painful disease, current pain management for NEC is often inadequate, and research on optimal analgesic therapy for these patients is lacking.
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