Raquel Pereira-Silva, Armando Teixeira-Pinto, Fani L Neto, Isabel Martins
{"title":"激活背侧网状核的μ-阿片受体可使雄性大鼠慢性关节痛的弥漫性毒性抑制控制转向痛觉亢进。","authors":"Raquel Pereira-Silva, Armando Teixeira-Pinto, Fani L Neto, Isabel Martins","doi":"10.1097/ALN.0000000000004956","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>The dorsal reticular nucleus is a pain facilitatory area involved in diffuse noxious inhibitory control (DNIC) through opioidergic mechanisms that are poorly understood. The hypothesis was that signaling of μ-opioid receptors is altered in this area with prolonged chronic inflammatory pain and that this accounts for the loss of DNICs occurring in this condition.</p><p><strong>Methods: </strong>Monoarthritis was induced in male Wistar rats (n = 5 to 9/group) by tibiotarsal injection of complete Freund's adjuvant. The immunolabeling of µ-opioid receptors and the phosphorylated forms of µ-opioid receptors and cAMP response element binding protein was quantified. Pharmacologic manipulation of μ-opioid receptors at the dorsal reticular nucleus was assessed in DNIC using the Randall-Selitto test.</p><p><strong>Results: </strong>At 42 days of monoarthritis, μ-opioid receptor labeling decreased at the dorsal reticular nucleus, while its phosphorylated form and the phosphorylated cAMP response element binding protein increased. [d-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin acetate (DAMGO) enhanced DNIC analgesia in normal animals (means ± SD: pre-DNIC: 126.9 ± 7.0 g; DNIC - DAMGO: 147.5 ± 8.0 g vs. DNIC + DAMGO: 198.1 ± 19.3 g; P < 0.001), whereas it produced hyperalgesia in monoarthritis (pre-DNIC: 67.8 ± 7.5 g; DNIC - DAMGO: 70.6 ± 7.7 g vs. DNIC + DAMGO: 32.2 ± 2.6 g; P < 0.001). An ultra-low dose of naloxone, which prevents the excitatory signaling of the μ-opioid receptor, restored DNIC analgesia in monoarthritis (DNIC - naloxone: 60.0 ± 6.1 g vs. DNIC + naloxone: 98.0 ± 13.5 g; P < 0.001), compared to saline (DNIC - saline: 62.5 ± 5.2 g vs. DNIC + saline: 64.2 ± 3.8 g). When injected before DAMGO, it restored DNIC analgesia and decreased the phosphorylated cAMP response element binding protein in monoarthritis.</p><p><strong>Conclusions: </strong>The dorsal reticular nucleus is likely involved in a facilitatory pathway responsible for DNIC hyperalgesia. The shift of μ-opioid receptor signaling to excitatory in this pathway likely accounts for the loss of DNIC analgesia in monoarthritis.</p><p><strong>Editor’s perspective: </strong></p>","PeriodicalId":7970,"journal":{"name":"Anesthesiology","volume":" ","pages":"1176-1191"},"PeriodicalIF":9.1000,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"μ-Opioid Receptor Activation at the Dorsal Reticular Nucleus Shifts Diffuse Noxious Inhibitory Controls to Hyperalgesia in Chronic Joint Pain in Male Rats.\",\"authors\":\"Raquel Pereira-Silva, Armando Teixeira-Pinto, Fani L Neto, Isabel Martins\",\"doi\":\"10.1097/ALN.0000000000004956\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Background: </strong>The dorsal reticular nucleus is a pain facilitatory area involved in diffuse noxious inhibitory control (DNIC) through opioidergic mechanisms that are poorly understood. The hypothesis was that signaling of μ-opioid receptors is altered in this area with prolonged chronic inflammatory pain and that this accounts for the loss of DNICs occurring in this condition.</p><p><strong>Methods: </strong>Monoarthritis was induced in male Wistar rats (n = 5 to 9/group) by tibiotarsal injection of complete Freund's adjuvant. The immunolabeling of µ-opioid receptors and the phosphorylated forms of µ-opioid receptors and cAMP response element binding protein was quantified. Pharmacologic manipulation of μ-opioid receptors at the dorsal reticular nucleus was assessed in DNIC using the Randall-Selitto test.</p><p><strong>Results: </strong>At 42 days of monoarthritis, μ-opioid receptor labeling decreased at the dorsal reticular nucleus, while its phosphorylated form and the phosphorylated cAMP response element binding protein increased. [d-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin acetate (DAMGO) enhanced DNIC analgesia in normal animals (means ± SD: pre-DNIC: 126.9 ± 7.0 g; DNIC - DAMGO: 147.5 ± 8.0 g vs. DNIC + DAMGO: 198.1 ± 19.3 g; P < 0.001), whereas it produced hyperalgesia in monoarthritis (pre-DNIC: 67.8 ± 7.5 g; DNIC - DAMGO: 70.6 ± 7.7 g vs. DNIC + DAMGO: 32.2 ± 2.6 g; P < 0.001). An ultra-low dose of naloxone, which prevents the excitatory signaling of the μ-opioid receptor, restored DNIC analgesia in monoarthritis (DNIC - naloxone: 60.0 ± 6.1 g vs. DNIC + naloxone: 98.0 ± 13.5 g; P < 0.001), compared to saline (DNIC - saline: 62.5 ± 5.2 g vs. DNIC + saline: 64.2 ± 3.8 g). When injected before DAMGO, it restored DNIC analgesia and decreased the phosphorylated cAMP response element binding protein in monoarthritis.</p><p><strong>Conclusions: </strong>The dorsal reticular nucleus is likely involved in a facilitatory pathway responsible for DNIC hyperalgesia. The shift of μ-opioid receptor signaling to excitatory in this pathway likely accounts for the loss of DNIC analgesia in monoarthritis.</p><p><strong>Editor’s perspective: </strong></p>\",\"PeriodicalId\":7970,\"journal\":{\"name\":\"Anesthesiology\",\"volume\":\" \",\"pages\":\"1176-1191\"},\"PeriodicalIF\":9.1000,\"publicationDate\":\"2024-06-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Anesthesiology\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1097/ALN.0000000000004956\",\"RegionNum\":1,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ANESTHESIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Anesthesiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1097/ALN.0000000000004956","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ANESTHESIOLOGY","Score":null,"Total":0}
μ-Opioid Receptor Activation at the Dorsal Reticular Nucleus Shifts Diffuse Noxious Inhibitory Controls to Hyperalgesia in Chronic Joint Pain in Male Rats.
Background: The dorsal reticular nucleus is a pain facilitatory area involved in diffuse noxious inhibitory control (DNIC) through opioidergic mechanisms that are poorly understood. The hypothesis was that signaling of μ-opioid receptors is altered in this area with prolonged chronic inflammatory pain and that this accounts for the loss of DNICs occurring in this condition.
Methods: Monoarthritis was induced in male Wistar rats (n = 5 to 9/group) by tibiotarsal injection of complete Freund's adjuvant. The immunolabeling of µ-opioid receptors and the phosphorylated forms of µ-opioid receptors and cAMP response element binding protein was quantified. Pharmacologic manipulation of μ-opioid receptors at the dorsal reticular nucleus was assessed in DNIC using the Randall-Selitto test.
Results: At 42 days of monoarthritis, μ-opioid receptor labeling decreased at the dorsal reticular nucleus, while its phosphorylated form and the phosphorylated cAMP response element binding protein increased. [d-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin acetate (DAMGO) enhanced DNIC analgesia in normal animals (means ± SD: pre-DNIC: 126.9 ± 7.0 g; DNIC - DAMGO: 147.5 ± 8.0 g vs. DNIC + DAMGO: 198.1 ± 19.3 g; P < 0.001), whereas it produced hyperalgesia in monoarthritis (pre-DNIC: 67.8 ± 7.5 g; DNIC - DAMGO: 70.6 ± 7.7 g vs. DNIC + DAMGO: 32.2 ± 2.6 g; P < 0.001). An ultra-low dose of naloxone, which prevents the excitatory signaling of the μ-opioid receptor, restored DNIC analgesia in monoarthritis (DNIC - naloxone: 60.0 ± 6.1 g vs. DNIC + naloxone: 98.0 ± 13.5 g; P < 0.001), compared to saline (DNIC - saline: 62.5 ± 5.2 g vs. DNIC + saline: 64.2 ± 3.8 g). When injected before DAMGO, it restored DNIC analgesia and decreased the phosphorylated cAMP response element binding protein in monoarthritis.
Conclusions: The dorsal reticular nucleus is likely involved in a facilitatory pathway responsible for DNIC hyperalgesia. The shift of μ-opioid receptor signaling to excitatory in this pathway likely accounts for the loss of DNIC analgesia in monoarthritis.
期刊介绍:
With its establishment in 1940, Anesthesiology has emerged as a prominent leader in the field of anesthesiology, encompassing perioperative, critical care, and pain medicine. As the esteemed journal of the American Society of Anesthesiologists, Anesthesiology operates independently with full editorial freedom. Its distinguished Editorial Board, comprising renowned professionals from across the globe, drives the advancement of the specialty by presenting innovative research through immediate open access to select articles and granting free access to all published articles after a six-month period. Furthermore, Anesthesiology actively promotes groundbreaking studies through an influential press release program. The journal's unwavering commitment lies in the dissemination of exemplary work that enhances clinical practice and revolutionizes the practice of medicine within our discipline.