In situ quantitative estimates of the age-related and diabetes-related changes in cerebral endothelial barrier antigen.

To determine whether ageing or diabetes, conditions known to alter the blood-brain barrier (BBB) is associated with changes in endothelial barrier antigen (EBA), a rat BBB-specific protein, in situ quantitation of forty vibrotome sections of cerebral tissue of 5 young (4 months old), 5 aged (26 months old) and 5 streptozotocin-induced diabetic rats after 4 weeks of diabetes were studied using immunohistologic techniques. The anti-EBA-stained microvessels were normalized against the total microvessels identified with either anti-EBA binding or anti-Glut-1 binding. The results indicate that the EBA-stained microvessels of the hippocampus, but not of other cerebral cortical areas or white matter, are reduced in aged rats (88.02 +/- 2.19% vs. 80.65 +/- 2.44%, P < 0.01). There were no significant changes in the diabetic rats. These results support the notion that changes in the BBB correlate with the aging of the central nervous system.