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Changes in convulsion susceptibility of lidocaine by alteration of brain catecholaminergic functions
Y Yoshimura1, T Dohi, S Tanaka
1Department of Oral and Maxillofacial Surgery, Hiroshima University School of Dentistry, Japan.
Abstract:
Influences of the manipulation of brain catecholaminergic neuronal activity on the incidence of lidocaine-induced convulsions in mice were studied and compared with those of pentylenetetrazol (PTZ)-induced convulsions. alpha-Methyl-p-tyrosine (alpha-MPT) decreased both brain noradrenaline (NA) and dopamine (DA) levels, and disulfiram decreased the NA level and increased the DA level. The incidence of lidocaine-induced convulsions was decreased by treatments with alpha-MPT and disulfiram, while that of PTZ was increased by either treatment. The incidence of lidocaine-induced convulsions was slightly, but not significantly increased by L-dihydroxyphenylalanine (L-DOPA), although the brain DA level was increased by L-DOPA. Methamphetamine and desipramine increased the incidences of lidocaine-induced convulsions. These results may suggest that brain catecholaminergic neurons, differing from their role in inhibiting control of PTZ-seizure, act to facilitate lidocaine-induced convulsions.
Insights
Brain catecholaminergic neurons facilitate lidocaine-induced convulsions, unlike their role in inhibiting pentylenetetrazol (PTZ)-induced seizures. Manipulating these neurons altered seizure incidence in mice.
Area of Science:
- Neuroscience
- Pharmacology
Background:
- Catecholaminergic neurons play a role in various neurological processes.
- Understanding their influence on drug-induced seizures is crucial for neuropharmacology.
Purpose of the Study:
- To investigate the role of brain catecholaminergic neuronal activity in lidocaine-induced convulsions.
- To compare these effects with pentylenetetrazol (PTZ)-induced convulsions.
Main Methods:
- Mice were treated with drugs affecting catecholamine levels: alpha-Methyl-p-tyrosine (alpha-MPT), disulfiram, L-dihydroxyphenylalanine (L-DOPA), methamphetamine, and desipramine.
- The incidence of lidocaine- and PTZ-induced convulsions was recorded.
Main Results:
- alpha-MPT and disulfiram decreased lidocaine-induced convulsions but increased PTZ-induced convulsions.
- L-DOPA showed a non-significant increase in lidocaine convulsions.
- Methamphetamine and desipramine increased lidocaine-induced convulsions.
Conclusions:
- Brain catecholaminergic neurons appear to facilitate lidocaine-induced convulsions.
- This contrasts with their inhibitory role in PTZ-induced seizures.
- These findings suggest distinct mechanisms for different drug-induced seizure types.