LOCAL CHANGES IN VASCULAR ARCHITECTURE FOLLOWING PARTIAL SPINAL-CORD LESION IN THE RAT

Lesions of the CNS induce a complex cascade of tissue reactions. The p urpose of this study was to determine the response of the vasculature to partial spinal cord transection. Adult rat spinal cords were lesion ed and then examined during acute, subacute, and chronic periods for t he presence of endothelial cells and blood vessels at the lesion site. The association of endothelial cells and astrocytes was examined immu nohistochemically (RECA-1 and glial fibrillary associated protein, res pectively). During the first 48 h following an incision lesion of the dorsal spinal cord, the vasculature was significantly decreased, concu rrently with the tissue loss due to primary and secondary degeneration . Subsequently, at 4 days postlesion, vasculature repair processes wer e evidenced by a significant increase in the number of vessels present at the lesion center. Blood vessels even formed in areas densely pack ed with macrophages and tissue debris. After 1 week, the number of blo od vessels declined in the lesion center and at the place of the formi ng caverns. These results show significant initial attempts at repair of the vasculature which do not, however, lead to the restoration of a compact tissue and cannot prevent the subsequent formation of caverns . (C) 1997 Academic Press.