Effects of discontinuous drug administration on the development of dopamine receptor supersensitivity during chronic trifluoperazine or cis-flupenthixol administration to rats.
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.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects*; D005475:Flupenthixol / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000032:analysis / Q000187:drug effects*; D013239:Stereotyped Behavior / Q000187:drug effects; D013892:Thioxanthenes / Q000494:pharmacology*; D014268:Trifluoperazine / Q000008:administration & dosage / Q000494:pharmacology*
D011954:Receptors, Dopamine; D013892:Thioxanthenes; D014268:Trifluoperazine; D005475:Flupenthixol; D001058:Apomorphine