The effects of dexmedetomidine and halothane on Fos expression in the spinal dorsal horn using a rat postoperative pain model.
We investigated the effect of an intrathecal injection of a selective alpha2 adrenergic receptor agonist, dexmedetomidine (Dex), and halothane anesthesia on Fos expression in the lumbar spinal dorsal horn after skin incision of the plantar surface of the hind paw, a postoperative pain model using rats. Fos immunoreactivity was induced particularly in the superficial layers of the spinal cord 2 h after surgery. Halothane anesthesia (0.5-1.5%) partially reversed Fos induction, but not in a dose-dependent manner. Preoperative spinal Dex (0.1-10 microg) dose-dependently reduced Fos immunoreactivity, while a relatively high dose of Dex (10 microg) was necessary to produce a profound effect. When used with halothane anesthesia, relatively low doses of Dex (1-3 microg) completely suppressed Fos induction in the superficial spinal layers. These findings indicate that preoperative Dex treatment may provide anesthesia that does not induce stress on spinal neurons.
Shimode
Noriko
N
Department of Anesthesiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan.
Fukuoka
Tetsuo
T
Tanimoto
Masaaki
M
Tashiro
Chikara
C
Tokunaga
Atsushi
A
Noguchi
Koichi
K
D000818:Animals; D020927:Dexmedetomidine / Q000494:pharmacology*; D005528:Foot / Q000601:surgery; D006221:Halothane / Q000494:pharmacology*; D010149:Postoperative Pain / Q000209:etiology / Q000378:metabolism*; D010812:Physical Stimulation / Q000009:adverse effects; D020671:Posterior Horn Cells / Q000187:drug effects / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D051381:Rats; D012016:Reference Values
D016760:Proto-Oncogene Proteins c-fos; D020927:Dexmedetomidine; D006221:Halothane