title: Some correlations between procaine-induced convulsions and monoamines in the spinal cord of rats.
abstract: The relationships between the convulsions induced by the local anesthetic procaine and monoamines in the spinal cord were investigated in rats. The levels of dopamine (DA) and serotonin (5-HT) in the spinal cord were time-dependently increased after procaine (170 mg/kg, i.p.), which induced clonic convulsions, but the level of norepinephrine (NE) was unchanged. The rats that died during convulsions had a marked increase in DA. Phenobarbital (25 mg/kg, s.c.) produced both depletion of DA and elevation of 5-HT in the spinal cord and completely protected rats against convulsions. A 5-HT precursor, 5-hydroxytryptophan (5-HTP; 20-80 mg/kg, i.p.), suppressed the convulsions in a dose-dependent manner as shown by a decrease in the incidence and a prolongation of the latency, but a DA precursor, 3,4-dihydroxyphenylalanine (L-DOPA; 20-80 mg/kg, i.p.), markedly shortened the latency. Furthermore, the effect of L-DOPA on the convulsions was inhibited by the combination of 5-HTP. alpha-Methyl-p-tyrosine (20-80 mg/kg, i.p.) or DL-p-chlorophenylalanine (20-80 mg/kg, i.p.), an inhibitor of NE and DA or 5-HT biosynthesis, had a slight effect on the convulsions. These results suggest that procaine causes significant elevations of rat spinal DA and 5-HT in the convulsive process and suggest that dopaminergic and serotonergic neurons may be associated with procaine-induced convulsions.
authors.affiliation: Department of Pharmacology, Tokyo Dental College, Chiba, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sawaki
authors.forename: M
authors.initials: M
authors.lastname: Kawaguchi
mesh_terms: D000818:Animals; D015306:Biogenic Monoamines / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D010634:Phenobarbital / Q000494:pharmacology; D011343:Procaine / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains; D012640:Seizures / Q000139:chemically induced*; D013116:Spinal Cord / Q000187:drug effects*
chemical_list: D015306:Biogenic Monoamines; D011343:Procaine; D010634:Phenobarbital