Decrease in plasma adiponectin level and increase in adiponectin immunoreactivity in cortex and hippocampus after traumatic brain injury in rats.

AIM Adiponectin plays an important role in the regulation of tissue inflammation. Recently, it has been reported that the plasma adiponectin levels in several acute illnesses decrease periodically, thus indicating that adiponectin may play a role in the inflammatory response in patients with acute illness. However, little is known about the effects of adiponectin following TBI. The aim of the present study was to examine the changes in the plasma adiponectin levels and the immunoreactivity of adiponectin in the brain after TBI. MATERIAL AND METHODS Adult male Sprague-Dawley rats were subjected to lateral fluid percussion injury using the Dragonfly device. Plasma adiponectin levels were determined by ELISA kit. Immunohistochemistry and Western blot analysis were performed to assess the immunoreactivity of adiponectin. RESULTS The plasma adiponectin levels gradually decreased and were significantly lower at 48 h and 72 h after injury than before injury. Immunohistochemistry and Western blot analysis showed that the adiponectin immunoreactivity was increased in the cerebral cortex at 24 hours after injury and in the hippocampus at 72 hours after injury. CONCLUSION Our findings suggest that adiponectin might participate in the pathophysiological process occurring after TBI.