A NOVEL ASPECT OF THROMBIN IN THE TISSUE REACTION FOLLOWING CENTRAL-NERVOUS-SYSTEM INJURY

Thrombin and two different types of control solutions (buffer and albu min) were continuously infused into the rat caudoputamen by an osmotic minipump. Routine histological studies with immunohistochemistry usin g antibodies for BrdU, GFAP, vimentin and laminin were carried out to assess infiltration of inflammatory cells, formation of edema, cell pr oliferation, and reactivity of astrocytes and mesenchymal cells. The n umber of inflammatory cells, number of BrdU positive cells, area and n umber of vimentin positive astrocytes, and the area of GFAP-positive r eactive astrocytes were quantitatively analyzed. In the thrombin group , pale tissue foci due to spongiosis were observed together with infil tration of inflammatory cells, proliferation of mesenchymal cells, and increase of vimentin positive astrocytes which was significantly diff erent from the control groups. The results suggest that thrombin plays an important role in inflammation, brain edema and reactive gliosis f ollowing CNS injury.