Vascular Leakage of Horseradish Peroxidase Following Acute Spinal Cord Injury

Abstract

Under normal CNS conditions, circulating horseradish peroxidase (HRP) fails to enter the perivascular spaces due to the presence of interendothelial tight junctions and the absence or low rate of pinocytotic activity. Under some conditions where the blood brain barrier (BBB) is altered, HRP leakage occurs. Possible routes of HRP leakage include increased pinocytotic activity, breakdown of the interendothelial tight junctions, and direct penetration across severely damaged endothelial cells. The modes of leakage may vary with the type of insult.Following acute compression of upper thoracic spinal cord (cat), leakage and distribution of HRP is confined to the posterocentral gray matter with minimal involvement of white matter (Fig. 1).