BACTERIAL COLLAGENASE DISRUPTS EXTRACELLULAR-MATRIX AND OPENS BLOOD-BRAIN-BARRIER IN RAT

Bacterial collagenase causes hemorrhagic necrosis of brain. We studied the enzyme's effect on blood-brain barrier (BBB) permeability and ext racellular matrix (ECM) structure by radiolabeled tracers and electron microscopy. Adult rats had intracerebral injection of bacterial colla genase. Brain uptake from blood of [C-14]sucrose was measured in 24 ra ts 0.5 h to 14 days after injection. 12 rats bad ultrastructural studi es 1 h after collagenase injection. Brain uptake of [C-14]sucrose is m aximally increased at 0.5 h, remaining significantly increased for 7 d ays. Ultrastructurally, some vessels had widening of basal lamina whil e others had severe disruption of basal lamina with stretching of endo thelial cells. We conclude that bacterial collagenase disrupts ECM and opens BBB.