Is the Phenomenon of Blood-Brain Barrier Disruption Induced with Mannitol All-or-None?

ABSTRACT

We evaluated the effect of mannitol-induced blood-brain-barrier disruption(BBBD) in 20 rats of the routine-dose mannitol group(1.75g/kg), 7 rats of the small-dose mannitol group(0.87g/kg), and 10 rats of the saline control group. Radioactivity ratios of brain section to plama in the routine dose mannitol group revealed a wide variation of 0.0134 to 0.1747 which was compared to the small dose mannitol group of 0.0107-0.0275 in the plasma albumin space and to the saline control group of 0.0051-0.0174. This result suggest that mannitol-induced BBBD may not be threshold event of all-or-none phenopomenon, but progressive graded reaction with various sensitivity.