Polyethylene Glycol-Catalase and Selenium Attenuate Blood-Brain Barrier Breakdown in Pentylenetetrazole-Induced Epileptic Seizures in Acute Hyperglycemic Rats.
Abstract number :
2.066
Submission category :
Year :
2001
Submission ID :
3096
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
C. Gurses, MD, Neurology, University of Istanbul, Istanbul, Turkey; M. Kaya, Prof, Physiology, University of Istanbul, Istanbul, Turkey; R. Kalayci, PhD, Research Institute for Experimental Medicine, Istanbul, Turkey; M. Kucuk, Ph D, Research Institute fo
RATIONALE: Severe epileptic seizures lead to acute cerebral metabolic changes (Cornford EM et al, Am J Physiol Heart Circ Physiol 279:H1346-54,2000) and exposure to high glucose may cause increased production of free radicals (Tesfamariam B et al Am J Physiol 263(2):H321-26,1992). We investigated the effects of antioxidants such as selenium and catalase on blood brain barrier (BBB) disruption during pentylenetetrazole-induced epileptic seizures in acute hyperglycemic rats.
METHODS: We used Wistar adult male rats (180 to 250 g body wt) in this study. They received the selenium (8 ppm/L) added to their drinking water for 8 weeks. Rats received polyethylene glycol-catalase (10,000 U/kg) intravenously 10 minutes before starting epileptic seizures. Acute hyperglycemia was induced an intraperitoneal injection of 50 % glucose. Epileptic seizure activity was produced by intravenous injection of pentylenetetrazol. Evans Blue (EB) dye was used as a marker for serum albumin extravasation. The concentration of EB dye was measured in the four regions of the brain tissue 45 minutes after intravenous injection of EB.
RESULTS: Extravasation of EB dye to the brain regions of animals in the epileptic group increased more when compared to saline-injected control animals (p[lt]0.01). The content of EB dye in the brain regions of animals in acute hyperglycemia plus epileptic group augmented more drastically rather than in saline, glucose, catalase, selenium and epileptic groups (p[lt]0.01). Transport of EB dye across the BBB was shown to increase in most regions of the brain in acute hyperglycemia plus status epilepticus, while that in the group of status epilepticus to selected regions of brain increased in a limited manner. The increased EB transfer from blood to the brain in status epilepticus and acute hyperglycemia plus status epilepticus was attenuated by the treatment with acute catalase and chronic selenium supplementation.
CONCLUSIONS: These data suggest that a partial reduction in the production of free radical species by catalase and selenium contributes to decreases in the content of EB dye across the BBB during pentylenetetrazole-induced status epilepticus in acute hyperglycemic rats.