Increased pain and inflammatory sensitivity in growth hormone-releasing hormone (GHRH) knockout mice

Publication date: Available online 10 July 2019Source: Prostaglandins & Other Lipid MediatorsAuthor(s): Sheila Leone, Annalisa Chiavaroli, Lucia Recinella, Giustino Orlando, Claudio Ferrante, Guya Diletta Marconi, Irene Gasparo, Alessandra Bitto, Roberto Salvatori, Luigi BrunettiAbstractGrowth hormone (GH) and GH-releasing hormone (GHRH), in addition to metabolic and endocrine effects, play a role in the modulation of pain and inflammation. We aimed to elucidate the consequences of GHRH deficiency on acute nociceptive stimulation and on both acute and chronic inflammatory stimuli in a mouse model of GH deficiency. Mice with generalized ablation of the GHRH gene (GHRH knock out, GHRHKO, -/-) were compared to wild type (GHRH +/+) mice.Responsiveness to acute nociceptive stimulation and to acute inflammatory stimulation was evaluated by conventional hot plate apparatus and formalin test, respectively. We also evaluated responsiveness to colonic inflammation induced both in vivo, after dextran sodium sulfate (DSS) treatment, or ex vivo, by incubating colon segments with bacterial lipopolysaccaride (LPS). Macroscopical and histological examinations were performed, prostaglandin (PG) E2 and 8-iso-PGF2α levels and cyclooxigenase (COX)-2 and tumor necrosis factor (TNF)-α gene expression were measured.Compared to controls, -/- mice showed decreased response latency during the hot plate test, and increased licking/biting time in formalin test, particularly in the second phase of infl...
Source: Prostaglandins and Other Lipid Mediators - Category: Lipidology Source Type: research