BACKGROUND: Burn injury (BI) pain consists of inflammatory and neuropathic components and activates microglia. Nicotinic alpha 7 acetylcholine receptors (α7AChRs) expressed in microglia exhibit immunomodulatory activity during agonist stimulation. Efficacy of selective α7AChR agonist GTS-21 to mitigate BI pain and spinal pain-mediators was tested. METHODS: Anesthetized rats after hind-paw BI received intraperitoneal GTS-21 or saline daily. Allodynia and hyperalgesia were tested on BI and contralateral paw for 21 days. Another group after BI receiving GTS-21 or saline had lumbar spinal cord segments harvested (day 7 or 14) to quantify spinal inflammatory-pain transducers or microglia activation using fluorescent marker, ionized calcium-binding adaptor protein (Iba1). RESULTS: BI significantly decreased allodynia withdrawal threshold from baseline of ~9–10 to ~0.5–1 g, and hyperalgesia latency from ~16–17 to ~5–6 seconds by day 1. Both doses of GTS-21 (4 or 8 mg/kg) mitigated burn-induced allodynia from ~0.5–1 to ~2–3 g threshold (P = .089 and P = .010), and hyperalgesia from ~5–6 to 8–9 seconds (P
No comments:
Post a Comment