Spinal astrocyte and microglial activation contributes to rat pain-related behaviors induced by the venom of scorpion Buthus martensi Karch.

Abstract

The present study investigated whether spinal astrocyte and microglia were activated in Buthus martensi Karch (BmK) venom-induced rat pain-related behaviors. The results showed that glial fibrillary acidic protein (GFAP) immunoreactivity indicative astrocyte activation in bilateral spinal cord started to increase by day 3, peaked at day 7 and gradually reversed at day 14 following intraplantar injection of BmK venom. Western blotting analysis confirmed GFAP expression was up-regulated by BmK venom. In contrast, bilateral spinal increase of OX-42 immunoreactivity indicative of microglial activation began at 4h peaked at day 1 and gradually reversed by days 3 to 7 after the administration of BmK venom. Pretreatment with either intrathecal injection of fluorocitrate or intraperitonial injection of minocycline, and two glial activation inhibitors, suppressed the spontaneous nociceptive responses, and prevented the primary thermal and bilateral mechanical hyperalgesia induced by BmK venom. The post-treatment with fluorocitrate or minocycline could not affect the mechanical hyperalgesia. Moreover, minocycline partially inhibited BmK venom-induced spinal c-Fos expression but lack of effects on BmK venom-induced paw edema. Taken together, the current study demonstrated that spinal astrocyte and microglial activation may contribute to BmK venom-induced rat pain-related behaviors. Thus, spinal glia may represent novel targets for effective treatment of pain syndrome associated with scorpion envenomation.

• Authors: Feng Jiang, Tong Liu, Ming Cheng, Xue-Yan Pang, Zhan-Tao Bai, Jing-Jing Zhou, Yong-Hua Ji
• Journal: European journal of pharmacology (Eur J Pharmacol) Vol. 623 Issue 1-3 Pg. 52-64 (Nov 25 2009) ISSN: 1879-0712 [Electronic] Netherlands
• PMID: 19782067 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Analgesics, Non-Narcotic
• Biomarkers
• Citrates
• Glial Fibrillary Acidic Protein
• Macrophage-1 Antigen
• Proto-Oncogene Proteins c-fos
• Scorpion Venoms
• fluorocitrate
• Minocycline

Topics

• Analgesics, Non-Narcotic (administration & dosage, metabolism, therapeutic use)
• Animals
• Astrocytes (drug effects, metabolism, physiology)
• Behavior, Animal (drug effects)
• Biomarkers (metabolism)
• Citrates (administration & dosage, therapeutic use)
• Drug Administration Schedule
• Edema (chemically induced)
• Glial Fibrillary Acidic Protein (metabolism)
• Hyperalgesia (chemically induced, drug therapy)
• Macrophage-1 Antigen (metabolism)
• Male
• Microglia (drug effects, metabolism, physiology)
• Minocycline (administration & dosage, metabolism, therapeutic use)
• Nociceptors (drug effects)
• Organ Specificity
• Pain (chemically induced, drug therapy, physiopathology)
• Pain Measurement
• Proto-Oncogene Proteins c-fos (metabolism)
• Rats
• Rats, Sprague-Dawley
• Scorpion Stings (drug therapy)
• Scorpion Venoms (administration & dosage, toxicity)
• Scorpions
• Spinal Cord (cytology, metabolism, pathology)
• Time Factors