RESUMO
PURPOSE: This study was carried out to investigate chronological changes of glutamate and gamma-aminobutyric acid (GABA) immunoreactivities in the anterior horn of the spinal cord after ischemia-reperfusion. MATERIALS AND METHODS: Spinal cord ischemia was induced by clamping the abdominal aorta for 15 minutes in New Zealand white rabbit, and then the spinal cord was reperfused. These animals were sacrificed at 0.5, 1, 3, 6, 12, 24 and 48 hours after ischemia-reperfusion. Spinal cord sections at the level of L7 were immunostained against glutamate and GABA. RESULTS: Glutamate immunoreactive neurons and fibers were first detected in the lamina IX at 30 minutes, but at 1 hour, the immunoreactivity returned to the control level. At 6 hour, glutamate immunoreactivity was observed around the blood vessels and its immunoreactivity increased between 6 and 12 hour. Thereafter the immunoreactivity decreased and eventually disappeared at 48 hours. GABA immunoreactivity increased in the anterior horn from 6 to 12 hours. Thereafter, GABA immunoreactivity decreased and eventually disappeared at 48 hours. CONCLUSION: These results suggest that the alteration of the glutamate immunoreactivity may occur much rapidly than that of GABA immunoreactivity in spinal anterior horn after ischemia-reperfusion.