Spinal cord glia activation following peripheral polyinosine-polycytidylic acid administration.
Effects of repeated intraperitoneal injections of polyinosine-polycytidylic acid on spinal cord cells were analysed. After each injection, the number of ED-1 microglia significantly increased in rat spinal cords. Expression of endothelial monocyte-activating polypeptide II, however, was not observed. The morphology of microglia indicated an incomplete activation state even after three repeated polyinosine-polycytidylic acid injections. Astrocyte activation was observed after the first injection using glial fibrillary acidic protein staining. Simultaneously with glia activation, hyperalgesia was observed, but the expression of P2X4 receptor, which is considered to be closely associated with hyperalgesia, on microglia was not detected. In sum, our data suggest that repeated peripheral injections of polyinosine-polycytidylic acid might alert the central nervous system through limited activation of microglia and astrocytes.
Zhang
Zhiren
Z
Institute of Brain Research, University of Tuebingen, D-72076 Tuebingen, Germany. zhangzhiren@yahoo.com
Trautmann
Katrin
K
Schluesener
Hermann J
HJ
D000818:Animals; D001253:Astrocytes / Q000187:drug effects* / Q000502:physiology; D016207:Cytokines / Q000378:metabolism; D006930:Hyperalgesia / Q000139:chemically induced / Q000378:metabolism; D007369:Interferon Inducers / Q000494:pharmacology*; D008297:Male; D017628:Microglia / Q000187:drug effects* / Q000502:physiology; D009363:Neoplasm Proteins / Q000378:metabolism; D009619:Nociceptors / Q000378:metabolism; D011070:Poly I-C / Q000494:pharmacology*; D016601:RNA-Binding Proteins / Q000378:metabolism; D051381:Rats; D011917:Rats, Inbred Lew; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D058848:Receptors, Purinergic P2X4; D013116:Spinal Cord / Q000166:cytology* / Q000187:drug effects / Q000502:physiology
D016207:Cytokines; D007369:Interferon Inducers; D009363:Neoplasm Proteins; C548228:P2rx4 protein, rat; D016601:RNA-Binding Proteins; D018048:Receptors, Purinergic P2; D058848:Receptors, Purinergic P2X4; C077219:small inducible cytokine subfamily E, member 1; D011070:Poly I-C