Effects of discontinuous drug administration on the development of dopamine receptor supersensitivity during chronic trifluoperazine or cis-flupenthixol administration to rats

• Published in: Psychopharmacology 1985-01, Vol.86 (1-2), p.228-232
• Main Authors: Murugaiah, K, Theodorou, A, Clow, A, Jenner, P, Marsden, C D
• Format: Article
• Language: English
• Subjects: Animals; Apomorphine - pharmacology; Corpus Striatum - drug effects; Flupenthixol - administration & dosage; Flupenthixol - pharmacology; Humans; Male; Rats; Rats, Inbred Strains; Receptors, Dopamine - analysis; Receptors, Dopamine - drug effects; Stereotyped Behavior - drug effects; Thioxanthenes - pharmacology; Trifluoperazine - administration & dosage; Trifluoperazine - pharmacology
• ISSN: 0033-3158; 1432-2072
• DOI: 10.1007/BF00431715

Rats received continuous or discontinuous administration of trifluoperazine or cis-flupenthixol in drinking water for up to 12 months. Continuous and discontinuous trifluoperazine administration had no consistent effect on apomorphine-induced stereotyped behaviour and there was no difference between drug treatments. Continuous and discontinuous cis-flupenthixol administration enhanced apomorphine-induced stereotypy, but there was no difference in the effect of the two drug treatments. Both continuous and discontinuous administration of trifluoperazine increased the number of specific striatal 3H-spiperone binding sites (Bmax). Over the period of treatment there was no difference in the effects of the different treatments. Continuous or discontinuous cis-flupenthixol intake did not increase Bmax after 6 or 12 months intake. Continuous or discontinuous neuroleptic treatment produced no difference in functional striatal dopamine receptor activity as judged by apomorphine-induced stereotyped behaviour. Ligand binding studies also suggest that the overall change in striatal receptor function is not affected by the use of a discontinuous drug regime.