Expression of C5a and its receptor following spinal cord ischemia reperfusion injury in the rat.

Abstract

Experimental study. To investigate the expression of C5a and its receptor after spinal cord ischemia reperfusion injury (SIRI) in rat. Department of Neurosurgery, the Second Affiliated Hospital, Xi'an Jiaotong University, Shaanxi Province, Xi'an, China Sprague Dawley rats were subjected to 1 h of infrarenal aorta occlusion to induce spinal cord ischemia. Spinal cord was reperfused for 12, 24, 48 h or 3 days separately after ischemia, respectively. Enzyme-linked immunosorbent assay was used to detect C5a in rat serum. Immunofluorescent staining was performed to detect the expression and cellular localization of C5aR in spinal cord following SIRI. Following SIRI, the motor behavior of the rats was significantly compromised. The serum concentration of C5a in the rat was elevated after SIRI and peaked at 24 h. C5aR was significantly upregulated in the lumbar spinal cord following SIRI and expressed on motor neurons and the microglia, but not astrocyte. There was no significant difference in the expression level of C5aR localized on motor neurons after SIRI. Remarkable upregulation of the C5aR may be associated with increased number of C5aR-positive microglia and elevated cellular expression level. This study provides the first evidence of the expression of C5a and its receptors in SIRI and suggests their possible contribution to SIRI in a rat model.