Alterations of lidocaine and pentylenetetrazol-induced convulsions by manipulation of brain monoamines.
The thresholds for pentylenetetrazol and lidocaine-induced clonic convulsions were significantly influenced by manipulation of brain biogenic amines. Pretreatment with inhibitors of monoamine synthesis, alpha-methyl-p-tyrosine and p-chlorophenylalanine, caused significant decreases in brain monoamine contents and pentylenetetrazol seizure threshold, while the threshold for lidocaine-induced convulsions was significantly increased by either treatment. Moreover, the inhibitor of dopamine-beta-hydroxylase, disulfiram, caused significant decrease in brain noradrenaline (NA) and significant increase in brain dopamine (DA) contents. The threshold for pentylenetetrazol-induced convulsions was decreased by treatment with disulfiram, while that of lidocaine was increased by the same treatment. Furthermore, treatment with L-dihydroxyphenylalanine (L-DOPA) caused significant increase in brain DA contents, while 5-hydroxytryptophan (5-HTP) treatment caused significant increase in brain 5-hydroxytryptamine (5-HT) contents, but the thresholds for lidocaine and pentylenetetrazol-induced convulsions were not influenced by either treatment. These results may suggest that the brain monoaminergic systems, different from their ability to inhibit control of pentylenetetrazol seizures, act to potentiate lidocaine-induced convulsions.
Abed
W T
WT
Department of Pharmacology, Faculty of Medicine, Jordan University of Science and Technology, Irbid.
D000818:Animals; D015306:Biogenic Monoamines / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D008012:Lidocaine / Q000633:toxicity*; D008297:Male; D010433:Pentylenetetrazole / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism*
D015306:Biogenic Monoamines; D008012:Lidocaine; D010433:Pentylenetetrazole