Experimental pneumococcal meningitis in rabbits: the increase of matrix metalloproteinase-9 in cerebrospinal fluid correlates with leucocyte invasion

Gelatinolytic activity of matrix metalloproteinases (MMPs), particularly MM P-9 and MMP-2, was studied by quantitative zymography in a rabbit model of bacterial meningitis during 24 h after inoculation with Streptococcus pneum oniae. In cerebrospinal fluid (CSF), MMP-2 was constitutively present and i ts level did not change during the experiment. In contrast, MMP-9, hardly d etectable in CSF of healthy animals, increased dramatically. The increase o f MMP-9 was correlated with both, an increase of CSF cell count and of tota l protein concentration. Intrathecal production of MMP-9 and MMP-2 was demo nstrated by zymography of equal amounts of total protein from CSF and serum . Homogenates, prepared from various cortical regions of infected rabbits d id not show increase of MMP activities. On the other hand, leucocytes isola ted from CSF expressed high levels of MMP-9 suggesting a significant contri bution of these cells to the elevation of MMP-9 activity in this body fluid . (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.