Type 1 diabetes exacerbates blood-brain barrier alterations during experimental epileptic seizures in an animal model

The aim of this study was to perform the effects of diabetes on the permeability of the blood-brain barrier (BBB) during pentylenetetrazole (PTZ)-induced epileptic attacks. For this propose, the animals were divided into four groups. These groups contained were intact, PTZ-treated, diabetic and PTZ-treated diabetic individuals, respectively. To evaluate the functioning of the BBB, Evans blue was used as a BBB permeability indicator, and the expressions of zonula occludens-1 and glial fibrillary acidic protein involving the functioning of the BBB were determined immunohistochemically. Also, the changes in the release of serum tumour necrosis factor-alpha and interleukin-10 and interleukin-12 were studied by using enzyme-linked immunosorbent assay method. BBB permeability in the seizures under diabetic conditions showed a considerable increase (p < 0·01) in all of the brain we studied. The immunoreactive staining intensity of zonula occludens-1 and glial fibrillary acidic protein was found reduced in the brain regions of diabetic rats (p < 0·01). However, the serum level of tumour necrosis factor-alpha increased in diabetes and diabetes + PTZ groups, and the serum level of interleukin-12 increased significantly in all experimental groups (p < 0·05). In conclusion, diabetes dramatically increases BBB damage during epileptic seizures, and it may be derived from an elevation of paracellular passage.