Endogenous serum albumin content in brain after short-lasting epileptic seizures

Epileptic seizures can transiently alter the blood-brain barrier. We have determined the content of extravasated endogenous serum albumin in the brain and its change with time after bicuculline (0.3 mg/kg) induced epileptic seizures of a few minutes' duration in conscious rats. The brains were perfused with saline in situ 5 min, 2 h, 24 h, 3 or 7 days after the injection of bicuculline. The content of endogenous serum albumin in the cerebral cortex, diencephalon, mesencephalon, pons and cerebellum was determined by rocket immunoelectrophoresis. At 5 min the extravasation was most marked in the diencephalon with levels above 99% of the confidence limit of control brains in 8 out of 9 brains. Higher levels were seen at 2 h than at 5 min in the cerebral cortex and the cerebellum. Since it is known that the barrier rapidly normalizes after seizures, these findings suggest redistribution probably along clearance pathways into the cerebrospinal fluid (CSF) and possibly re-entry of albumin into the parenchyma from the CSF. Four out of 6 rats still had increased albumin levels in the cerebral cortex at 24 h. At 72 h and 7 days no values differed from controls.