Ovarian Hormone-dependent and Spinal ERK Activation-regulated Nociceptive Hypersensitivity in Female Rats with Acid Injection-induced Chronic Widespread Muscle Pain.

ABSTRACT: Symptoms of chronic widespread muscle pain (CWP) meet most of the diagnostic criteria for fibromyalgia syndrome, which is prevalent in females. We used an acid injection-induced muscle pain (AIMP) model to mimic CWP. After female rats received an ovariectomy (OVX), acid saline solution was injected into the left gastrocnemius muscle. Time courses of changes in pain behaviours and p-ERK in the spinal cord were compared between groups. Intrathecal injections of oestradiol (E2) to the OVX group before two acid injections and E2 or progesterone (P4) injections in male rats were compared to evaluate hormone effects. We found that repeated acid injections produced mechanical hypersensitivity and enhanced p-ERK expression in the spinal dorsal horn. OVX rats exhibited significantly less tactile al

SUBMITTER: Chang JH 

PROVIDER: S-EPMC6395742 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature