BACKGROUND: Oxidative stress plays an important role in the pathophysiology of epilepsy. Glutathione, known as one of the compounds of antioxidant defense, has been shown to inhibit convulsions. Nitric oxide has a pr...BACKGROUND: Oxidative stress plays an important role in the pathophysiology of epilepsy. Glutathione, known as one of the compounds of antioxidant defense, has been shown to inhibit convulsions. Nitric oxide has a proconvulsant effect on a pentylenetetrazole-induced animal model. OBJECTIVE: To evaluate the effects of glutathione administration on nitric oxide levels in brain regions of convulsive and kindling pentylenetetrazole-induced seizure models. DESIGN, TIME, AND SETTING: A randomized, controlled, animal experiment. The study was performed at the Department of Physiology, Gaziantep University and Department of Chemistry-Biochemistry,Kahramamaras Sutcu Imam University in 2006. MATERIALS: Pentylenetetrazole and glutathione were purchased from Sigma, USA. METHODS: A total of 80 mice were assigned to 8 groups (n = 10): normal control, saline control (1 mL normal saline), convulsive pentylenetetrazole (single intraperitoneal administration of pentylenetetrazole, 60 mg/kg), convulsive pentylenetrazole plus glutathione (single administration of 60 mg/kg pentylenetetrazole and 200 mg/kg glutathione), five-dose glutathione (intraperitoneal injection of 200 mg/kg glutathione respectively at 1, 3, 5, 7, and 10 days), single-dose glutathione (single administration of 200 mg/kg glutathione), pentylenetetrazole kindling (intraperitoneal administration of pentylenetetrazole of 40 mg/kg at 1,3, 5, 7, and 10 days), and pentylenetetrazole kindling plus glutathione group (intraperitoneal injection of 40 mg/kg pentylenetetrazole and 200 mg/kg glutathione respectively at 1, 3, 5, 7, and 10 days). MAIN OUTCOME MEASURES: All mice were sacrificed 1 hour after the last administration. Brain nitric oxide levels were determined by spectrophotometry. RESULTS: There were no significant differences in nitric oxide levels between the normal control, saline control, five-dose glutathione, and single-dose glutathione groups (P 〉 0.05). Nitric oxide levels in the cerebral hemisphere and cerebellum were significantly less in the convulsive pentylenetetrazole group, compared with the convulsive pentylenetetrazole plus glutathione group (P 〈 0.01), and levels in the pentylenetetrazole kindling group were remarkably greater than the remaining groups (P 〈 0.01 ). Brain nitric oxide levels in all groups gradually decreased from the right brain stem to the left brain stem, cerebellum, left cerebral hemisphere, and right cerebral hemisphere. CONCLUSION: Glutathione regulated nitric oxide levels in various brain regions of pentylenetetrazole-induced kindling models, and did not affect nitric oxide levels in the control mice. These results indicated that glutathione played a role when nitric oxide was over-produced. In addition, the brain stem exhibited the highest levels of nitric oxide in both control mice and pentylenetetrazole-induced kindling models.展开更多
文摘BACKGROUND: Oxidative stress plays an important role in the pathophysiology of epilepsy. Glutathione, known as one of the compounds of antioxidant defense, has been shown to inhibit convulsions. Nitric oxide has a proconvulsant effect on a pentylenetetrazole-induced animal model. OBJECTIVE: To evaluate the effects of glutathione administration on nitric oxide levels in brain regions of convulsive and kindling pentylenetetrazole-induced seizure models. DESIGN, TIME, AND SETTING: A randomized, controlled, animal experiment. The study was performed at the Department of Physiology, Gaziantep University and Department of Chemistry-Biochemistry,Kahramamaras Sutcu Imam University in 2006. MATERIALS: Pentylenetetrazole and glutathione were purchased from Sigma, USA. METHODS: A total of 80 mice were assigned to 8 groups (n = 10): normal control, saline control (1 mL normal saline), convulsive pentylenetetrazole (single intraperitoneal administration of pentylenetetrazole, 60 mg/kg), convulsive pentylenetrazole plus glutathione (single administration of 60 mg/kg pentylenetetrazole and 200 mg/kg glutathione), five-dose glutathione (intraperitoneal injection of 200 mg/kg glutathione respectively at 1, 3, 5, 7, and 10 days), single-dose glutathione (single administration of 200 mg/kg glutathione), pentylenetetrazole kindling (intraperitoneal administration of pentylenetetrazole of 40 mg/kg at 1,3, 5, 7, and 10 days), and pentylenetetrazole kindling plus glutathione group (intraperitoneal injection of 40 mg/kg pentylenetetrazole and 200 mg/kg glutathione respectively at 1, 3, 5, 7, and 10 days). MAIN OUTCOME MEASURES: All mice were sacrificed 1 hour after the last administration. Brain nitric oxide levels were determined by spectrophotometry. RESULTS: There were no significant differences in nitric oxide levels between the normal control, saline control, five-dose glutathione, and single-dose glutathione groups (P 〉 0.05). Nitric oxide levels in the cerebral hemisphere and cerebellum were significantly less in the convulsive pentylenetetrazole group, compared with the convulsive pentylenetetrazole plus glutathione group (P 〈 0.01), and levels in the pentylenetetrazole kindling group were remarkably greater than the remaining groups (P 〈 0.01 ). Brain nitric oxide levels in all groups gradually decreased from the right brain stem to the left brain stem, cerebellum, left cerebral hemisphere, and right cerebral hemisphere. CONCLUSION: Glutathione regulated nitric oxide levels in various brain regions of pentylenetetrazole-induced kindling models, and did not affect nitric oxide levels in the control mice. These results indicated that glutathione played a role when nitric oxide was over-produced. In addition, the brain stem exhibited the highest levels of nitric oxide in both control mice and pentylenetetrazole-induced kindling models.