Effects of nimodipine on l-glutamate-induced seizures and Ca2+ influx in hippocampus in freely moving rats.
Seizure (EEG) was studied in rats unilaterally injected in the dorsal hippocampus with l-glutamate (Glu). Extracellular Ca2+ content [(Ca2+)e] in the injected area was assessed by brain microdialysis coupled to automatic atomic absorption spectrophotometry. In this experimental epileptic model, an inhibition of Glu-stimulated epileptic activity and a fall in (Ca2+)e by nimodipine (Nim, 100 micrograms.kg-1) were seen. The spike- and wave-burst frequency was reduced from 30 to 5 bursts.min-1 (P less than 0.01, n = 8). Nim 25 and 50 micrograms.kg-1, without anticonvulsant activity, did not prevent the drop in (Ca2+)e. These results indicate that Nim exerts an antiepileptic effect on Glu-induced epilepsy. The mechanisms may be involved in blocking Ca2+ influx into neurons.
Lu
Y M
YM
Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing.
Zhang
J T
JT
Zhao
F Q
FQ
Li
F
F
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D004569:Electroencephalography / Q000187:drug effects; D004827:Epilepsy / Q000139:chemically induced / Q000503:physiopathology*; D005971:Glutamates; D006624:Hippocampus / Q000378:metabolism*; D007276:Injections, Intraventricular; D008297:Male; D009474:Neurons / Q000378:metabolism; D009553:Nimodipine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D005971:Glutamates; D009553:Nimodipine; D002118:Calcium