RESUMO
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.
Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Epilepsia/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Astrócitos/metabolismo , Glicemia/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Barreira Hematoencefálica/química , Convulsivantes/farmacologia , Citocinas/sangue , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/fisiopatologia , Epilepsia/fisiopatologia , Feminino , Pentilenotetrazol/farmacologia , Permeabilidade , Ratos Wistar , Estreptozocina , Proteína da Zônula de Oclusão-1/metabolismoRESUMO
The aim of this study was to compare the effects of hypoglycemia and induced convulsions on the blood-brain barrier permeability in rats with or without lifelong administration of sodium selenite. There is a significant decrease of the blood-brain barrier permeability in three brain regions of convulsive, hypoglycemic male rats treated with sodium selenite when compared to sex-matched untreated rats (p<0.05), but the decrease was not significant in female rats (p>0.05). The blood-brain barrier permeability of the left and right hemispheres of untreated, moderately hypoglycemic convulsive rats of both genders was better than their untreated counterparts (p<0.05). Our results suggest that moderate hypoglycemia and lifelong treatment with sodium selenite have a protective effect against blood-brain barrier permeability during convulsions and that the effects of sodium selenite are gender-dependent.
Assuntos
Barreira Hematoencefálica/metabolismo , Hipoglicemia/metabolismo , Convulsões/metabolismo , Caracteres Sexuais , Selenito de Sódio/administração & dosagem , Selenito de Sódio/farmacologia , Animais , Pressão Sanguínea , Feminino , Masculino , Ratos , Ratos Wistar , Selenito de Sódio/metabolismo , Fatores de TempoRESUMO
Our purpose in this study was to investigate the protective effects of selenium and vitamin E on the blood-brain barrier (BBB) permeability in rats with convulsion under hyperthermic conditions. To eliminate the effect of sex on BBB, we performed our study on 4- to 5-week-old prepubertal rat pups. Evans-blue was used as a BBB tracer. Convulsions were induced by administration of i.p. pentylenetetrazol. In the selenium group, 4 ppm selenium was added to the drinking water for 4-5 weeks. Vitamin E was administered at 700 mg/kg ip. It was shown that the convulsions, both under normothermic and hyperthermic conditions, caused widespread increase in the BBB permeability (p < 0.05). In addition, a significant difference was observed among female and male rats (f [1, 102] = 6.387, p < 0.05). In convulsions under normothermic conditions, there was a further increase in the BBB permeability (F[3, 102] = 43.534, p < 0.001) and a greater increase of permeability in males compared to females (F[1, 102] = 6.387, p < 0.05). Selenium and vitamin E significantly decreased the BBB destruction caused by convulsions under hyperthermic conditions in males (p < 0.05). Treatment with selenium or vitamin E has beneficial effects on the BBB breakdown during convulsions. But gender differences are very important in BBB permeability under pathological conditions and antioxidant treatments.
