ascorbic-acid and Epilepsy--Tonic-Clonic

Vitamin C helps to prevent brain oxidative stress and participate in the synthesis of progesterone. It also possesses a progesterone-like effect and acts synergistically with progesterone on the brain. Progesterone and its metabolites, but also vitamin C have been associated with anticonvulsant effects. We evaluated the progesterone concentration 30min and 24h after the last administration of vitamin C (500mg/kg, i.p. for five days). We also evaluated how vitamin C altered pentylenetetrazol (PTZ)-induced seizures by measuring the onset latency of seizures, percentage of incidence and mortality as well as amino acid levels after seizures. Vitamin C treatment alone increased basal progesterone concentrations to 531% after 30min compared to 253% after 24h. Furthermore, vitamin C significantly increased the latency to the first myoclonic, clonic and tonic seizure induced by PTZ (80mg/kg, i.p.) and decreased the percentage of incidence of clonic and tonic seizures as well as the mortality rate. Changes in tissue concentration of amino acids were primarily observed at 24h after vitamin C treatment. Our results suggest that vitamin C together with progesterone and/or its metabolites are involved in the protection against PTZ-induced seizures in immature rats.

Topics: Animals; Anticonvulsants; Ascorbic Acid; Aspartic Acid; Brain Chemistry; Chromatography, High Pressure Liquid; Convulsants; Dose-Response Relationship, Drug; Epilepsies, Myoclonic; Epilepsy, Tonic-Clonic; Female; gamma-Aminobutyric Acid; Glutamates; Glutamine; Male; Pentylenetetrazole; Progesterone; Rats; Rats, Sprague-Dawley; Seizures; Vitamins

As an index of oxidative status, we analyzed ascorbyl radical generation during and after kainate-induced seizures in mouse hippocampus, using an ESR spectrometer equipped with a special tissue-type quartz cell. A specific doublet ESR spectrum was observed after seizures, and the g value and the hyperfine coupling constant (hfcc) of the spectrum were identical with those of ascorbyl radical itself. Antiepileptic zonisamide inhibited the generation of ascorbyl radical accompanying the seizures.

Topics: Animals; Anticonvulsants; Ascorbic Acid; Electron Spin Resonance Spectroscopy; Epilepsy, Tonic-Clonic; Excitatory Amino Acid Agonists; Free Radicals; Hippocampus; Isoxazoles; Kainic Acid; Male; Manganese Compounds; Mice; Oxides; Seizures; Zonisamide