Effects of extracellular ATP on GFAP expression after spinal cord injury in rats

Abstract

Objective To investigate the effects ofextracellular adenosine triphosphate (ATP)on the expression of glial fibrillary acidic protein (GFAP) and the recovery of motor function after spinalcord injury in rats. Methods Six rats were selected as the normal control group randomly from 66adult healthy Wistar rats, and the rest 60 rats were divided into 2 groups after contusion injury wasperformed by the weight drop method with Allen impactor: group A (ATP group) and group B (controlgroup), and every group contained 30 rats. At day 1, 3, 7, 14, and 28 after injury, the rats were killed, andthe expression of GFAP was detected with immunohistochemistry. The expression of GFAP in theadjacent area was semi-quantitatively analyzed with a computer image analysis system; the recovery ofmotor function after spinal cord injury was assessed with improved Tarlov scores. Results Theexpression of GFAP was significantly higher in group A than in Group B after spinal cord injury in rats(P<0.05), and significant difference was also revealed in the expression of GFAP between the 2 groups atday 7, 14 and 28 after injury (P<0.05). At day 14 and 28, Tarlov scores were significantly higher in groupA than in group B (P<0.05). Conclusion Extracellular ATP can promote the expression of GFAP inspinal cord, and may be helpful to the recovery of motor function after spinal cord injury in rats. Key words: Spinal cord injury; Adenosine triphosphate; Glial fibrillary acidic protein