Abstract
To our knowledge, it is the first study which investigates the induction of neuroinflammation in rats by acidic-saline model of fibromyalgia. It is well known that the hippocampus has a fundamental role in pain perception and the astrocytes play a crucial role in pain signaling. Our aim is to evaluate the ability of dexmedetomidine to attenuate the inflammatory response induced in astrocytes. In a group of healthy rats, induction of chronic muscle pain by I.M. injection with 100 µL of acidic saline on day 0 and 5, resulted in peripheral sensitization (measured by von-Frey test) and significant (p<0.05) increase in IL-1β (160.2±1.1 to 335.2±1.8), IL-6 (100.1±1.4 to 202.4±1.1) and TNF-α (60.0±0.7 to 115.5±1). Light and electron microscopy revealed degenerative changes of the hippocampus and reactive astrogliosis. Immunohistochemistry showed increased expression of GFAP and iNOS. Surprisingly, treatment with a single dose of an α2-adrenergic agonist, dexmedetomidine (5µg/kg) i.p attenuated these changes. This trial raises a possibility of dexmedetomidine’s direct effect on astrocytes, peripheral action is also suggested