Harmine-, LON-954- and 5-hydroxytryptophan-induced tremors in rats withdrawn from ethanol.

Abstract

The tremors induced by harmine, LON-954 (N-carbamoyl-2-(2,6-dichlorophenyl)acetamidine hydrochloride) and 5-hydroxytryptophan (5-HTP) were studied in control rats and in rats withdrawn for 16-48 hrs from 6 to 9 days' ethanol administration. The frequencies and the intensities of the tremors were determined electronically. In control rats the frequency spectra of the tremors induced by harmine (20 mg/kg) and LON-954 (10 mg/kg) showed a narrow peak frequency at about 10 Hz. Atropine (1.2 mg/kg) altered neither the frequency nor the intensity of these tremors. 5-HTP (50 mg/kg) when given 3.5 hrs after iproniazid (100 mg/kg) induced tremor with peak frequencies at 6-7 Hz and 12 Hz. In ethanol-withdrawn rats treated with harmine or LON-954 the frequency analysis of tremor revealed a narrow peak frequency at about 12 Hz, which was neither the characteristic frequency of ethanol withdrawal tremor (6 Hz) nor that of harmine or LON-954 (10 Hz). The intensity of both harmine- and LON-954-induced tremor was significantly increased in ethanol-withdrawn rats. The ethanol-withdrawn rats were markedly sensitized to the effect of iproniazid+ 5-HTP, shown by deaths. The peak frequencies of this tremor were the same as those in control rats. The results suggest that harmine-induced tremor involves a dopaminergic-5-HT'ergic imbalance and the tremor induced by LON-954 a dopaminergic-cholinergic imbalance in the brain. The tremor in ethanol-withdrawn rats seems to be mediated by alterations in the activity of the cerebral 5-HT'ergic system.

• Authors: P Gothóni
• Journal: Acta pharmacologica et toxicologica (Acta Pharmacol Toxicol (Copenh)) Vol. 57 Issue 1 Pg. 40-6 (Jul 1985) ISSN: 0001-6683 [Print] Denmark
• PMID: 3876687 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Alkaloids
• Ethanol
• Harmine
• LON 954
• Urea
• Physostigmine
• 5-Hydroxytryptophan

Topics

• 5-Hydroxytryptophan (pharmacology)
• Alkaloids (pharmacology)
• Animals
• Ethanol (adverse effects)
• Harmine (pharmacology)
• Male
• Physostigmine (pharmacology)
• Rats
• Rats, Inbred Strains
• Substance Withdrawal Syndrome (physiopathology)
• Tremor (chemically induced)
• Urea (analogs & derivatives, pharmacology)