LUCIFERASE - A SENSITIVE AND QUANTITATIVE PROBE FOR BLOOD-BRAIN-BARRIER DISRUPTION

A novel method for quantitative analysis of blood-brain barrier (BBB) disruption is described, using luciferase as a probe in a murine model system. Purified luciferase was delivered to mouse brain by osmotic B BB disruption with hypertonic mannitol; control animals received an in tracarotid inoculation of saline prior to infusion of luciferase. Deli very of luciferase to brain tissue was then assessed by enzyme assay o f tissue extracts, and by immunohistochemical staining. Luciferase act ivity in the brain of mannitol-treated animals was found to be signifi cantly elevated (approx. sevenfold), when compared to activity in cont rol (saline-treated) mice. This finding was confirmed by quantitative immunohistochemical staining of tissue sections, using a luciferase-sp ecific antibody. These studies showed that there was an eight-fold ele vation in the level of extravascular luciferase particles within the b rain of mannitol-treated animals, as compared to controls. Taken toget her these data show that purified recombinant luciferase can be used a s a sensitive probe, with which to study the integrity of the BBB. (C) 1998 Elsevier Science B.V. All rights reserved.