Metabotropic glutamate receptor 5 and dorsal raphe serotonin release in inflammatory pain in rat.

Eur J Pharmacol

Department of Experimental Medicine, Section of Pharmacology "L. Donatelli", Faculty of Medicine and Surgery, II University of Naples, via Costantinopoli 16, 80138 Naples, Italy.

Published: May 2004

In this study, we evaluated the effects of 2-methyl-6-(phenylethynyl)-pyridine (MPEP), a selective antagonist of metabotropic glutamate subtype 5 receptors (mGlu(5)), delivered through different paths on dorsal raphe serotonin (5-HT) and on thermoceptive responses in rats with inflammatory pain. Intraplantar formalin and carrageenan increased 5-HT (137+/-11% and 212+/-6% of pre-injection baseline, respectively) and reduced nociceptive threshold (23+/-7% and 19+/-3% of pre-injection baseline, respectively). MPEP (2 mg/kg i.p.) further enhanced formalin and carrageenan-induced 5-HT increases (180+/-11% and 260+/-12% of pre-injection baseline, respectively) and reduced thermal hyperalgesia (71+/-8% and 80+/-10% of pre-injection baseline, respectively). MPEP (1 mM) through microdialytic probe into the dorsal raphe did not change formalin- or carrageenan-induced 5-HT increases (147+/-10% and 189+/-10% of pre-injection baseline, respectively) and thermal hyperalgesia (35+/-8% and 25+/-9% of pre-injection baseline, respectively). Finally, MPEP (30 nmol/rat) into the hind paw reduced the formalin- and carrageenan-induced 5-HT increase (108+/-3% and 126+/-7% of pre-injection baseline, respectively) and thermal hyperalgesia (77+/-6% and 117+/-7% of pre-injection baseline, respectively). Dorsal raphe serotonergic neurons activity increased following a peripherally induced inflammatory injury. In these conditions, peripheral but not dorsal raphe mGlu(5) receptors blockade prevented over activation of dorsal raphe serotonergic neurons and reversed thermal hyperalgesia.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejphar.2004.03.063DOI Listing

Publication Analysis

Top Keywords

pre-injection baseline
32
dorsal raphe
24
thermal hyperalgesia
16
carrageenan-induced 5-ht
12
metabotropic glutamate
8
raphe serotonin
8
inflammatory pain
8
pre-injection
8
baseline
8
baseline reduced
8

Similar Publications

Background: Adhesive capsulitis (AC) is a common cause of shoulder disability. Interventional procedures are used along with many other treatment methods. There are insufficient studies directly comparing the superiority of suprascapular nerve block (SSNB) and intra-articular shoulder injection (IAI) techniques, which are frequently used interventional methods in treatment.

View Article and Find Full Text PDF

Background: Mobile health devices are increasingly available, presenting exciting opportunities to remotely collect high-frequency, electronic patient-generated health data (ePGHD). This novel data type may provide detailed insights into disease activity outside usual clinical settings. Assessing treatment responses, which can be hampered by the infrequency of appointments and recall bias, is a promising, novel application of ePGHD.

View Article and Find Full Text PDF

Surgical oncology often requires the use of contrast-enhanced cross-sectional imaging preoperatively to characterize solitary tumours and identify sentinel lymph nodes. Intraoperative optical guidance can effectively aid tissue-sparing tumour excision and locate sentinel lymph nodes. Nanotrast-CF800 (CF800) is a novel dual-modality contrast agent, which co-encapsulates iohexol and indocyanine green (ICG) within a liposomal nanoparticle.

View Article and Find Full Text PDF
Article Synopsis
  • Catastrophizing, a mental process that can worsen pain outcomes, was studied in patients receiving steroid injections for chronic low back pain (cLBP), focusing on how their levels of catastrophizing might change post-treatment.
  • In a study of 128 patients, assessments using the Pain Catastrophizing Scale (PCS) and Brief Pain Inventory (BPI) showed no significant change in PCS scores one month after injections, suggesting that catastrophizing may not be a stable predictor of pain response.
  • The analysis found that the emotional impact of pain on relationships, enjoyment, and mood (REM) was a key predictor of post-injection PCS scores, while other factors like pain severity and demographics did not significantly influence changes in catastrophizing
View Article and Find Full Text PDF

To assess the incidence, risk factors, and treatment outcomes in intravitreal triamcinolone acetonide injection (IVTA) induced intraocular pressure rise and to compare IOP rise in 1-mg and 2-mg IVTA. Prospective observational study conducted in all eyes receiving IVTA. Any pre-existing glaucoma and patients who received IVTA or dexamethasone implant in the last 6 months were excluded.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!