EXPRESSION OF THE 27,000 MOL WT HEAT-SHOCK PROTEIN FOLLOWING KAINIC ACID-INDUCED STATUS EPILEPTICUS IN THE RAT

Western analysis and immunohistochemistry were used to determine the t ime-course and the distribution of the 27,000 mol. wt heat shock prote in, Hsp27, in rat brain following systemic administration of kainic ac id. No Hsp27 immunoreactivity was detected in naive control animals or in rats that failed to develop status epilepticus. Hsp27 immunoreacti vity was detected as early as 12 h in the parietal cortex, piriform co rtex and the hippocampus of rats that developed status epilepticus. Th e number of cells expressing Hsp27 and the intensity of Hsp27 immunore activity were increased 24 h after kainic acid administration. Hsp27 i mmunoreactivity was still observed seven days post-kainic acid injecti on. The morphology of the Hsp27-positive cells and double immunofluore scence against Hsp27 and glial fibrillary acidic protein revealed that Hsp27-positive cells were astrocytes. In addition, the distribution o f Hsp27 suggested that astrocytic Hsp27 was dependent on excitation-in duced metabolic stress rather than the direct effect of kainic acid on astrocytes. Copyright (C) 1996 IBRO.