Reactive glial cells express a vitronectin-like protein in the hippocampus of epileptic rats

Injection of kainic acid into the amygdala induces in addition to a local cell loss a seizure related distal damage of the hippocampal complex, in particular in the CA3 field and hilus. This neuronal lesion is associated with hypertrophy and proliferation of astroglial cells which start around 3 days after kainate and peaks within 20 days of kainate. We now report that reactive astrocytes are labelled with antibodies against vitronectin in the CA3 field and hilus. In the present study we also exclude that the presence of vitronectin into the brain is due to an extravasation from serum throughout a blood brain barrier leakage. The present results constitute the first demonstration for a glial expression of vitronectin in vivo. Vitronectin is an extracellular matrix glycoprotein involved in axonal growth. The glial expression of vitronectin may therefore contribute to the synaptic remodeling of mossy fibers induced in the hippocampus by such treatment.