Acute hyperglycemia augments blood-brain barrier damage in experimental status epilepticus

Abstract

Experimental data indicate that hyperglycemia does not augment noronal damage in experimental status epilepticus. However, hyperglycemia has been shown to worsen acute blood-brain barrier (BBB) injury after forebrain ischemia in rats. The aim of this study is to determine whether acute hyperglycemia will exaggregate the BBB consequences of normoglycemic status epilepticus. Acute hyperglycemia was induced by intraperitoneal injection of glucose solution in rats. We used the tracer Evans blue (EB) as an indicator of increased vascular permeability. Epileptic seizures were induced by pentylenetetrazole (PTZ). At the end of experiments, rats were perfused with 0.9% saline via left ventricle. Evans blue albumin extravasation was visually evaluated and measured spectrophotometrically in 4 brain regions. The content of the EB in the group of hyperglycemia plus status epilepticus was extremely higher compared with status epilepticus in the normoglycemic conditions (p < 0.01). Under acute hyperglycemia plus status epilepticus conditions, hyperglycemia significantly worsens the degree of acute BBB breakdown compared with normoglycemic status epilepticus. These results suggest that hyperglycemia appears to be an important risk factor for additional increase in BBB permeability following hyperglycemia plus status epilepticus-induced BBB disruption.