Elastase Given Intracisternally Opens Blood-Brain Barrier in Newborn Piglets

Abstract

The effect of elastase on the blood-brain barrier (BBB) permeability was intravitally studied by fluorescence photomacroscope using the open cranial window technique in newborn piglets. Eleven animals (group 1) were given intracisternal injection of porcine elastase (1.0 micrograms), while 7 piglets served as controls (group 2). Elastase administration resulted in spotty sodium fluorescein (MW 376 daltons) extravasations in pial venules in all animals of group 1 78 +/- 4 min (mean +/- SEM) after the challenge, and in a 2-fold increase (p < 0.05) in brain sodium fluorescein uptake both in occipital cortex and white matter. The concentration of elastase-alpha 1-proteinase inhibitor complex increased significantly (p < 0.05) in cerebrospinal fluid samples in group 1, 2 and 4 h after the injection, while it did not change in sera. A significant pleocytosis and leukocytosis was also seen in group 1, while there was no change in laboratory data and BBB remained tight in group 2. BBB permeability changes during neonatal meningitis may be caused, at least partially, by elastase.