Supersensitivity of dopamine-autoreceptors. The effect of gammabutyrolactone in long-term haloperidol treated rats.
Rats were injected daily with haloperidol, 0.5 mg/kg i.p. for a period of 16 days. 24 hours after the last injection of haloperidol these rats were challenged with gammabutyrolactone in doses of 200-750 mg/kg i.p. The ensuing increase in neostriatal dopa-accumulation was significantly lower than in rats not previously treated with haloperidol. Since the increase in dopa-accumulation following GBL-treatment is most probably independent of postsynaptically located DA-receptors the difference between the experimental series is explained in terms of reduced feedback activation of DA-synthesis due to the increased sensitivity of presynaptically located DA-autoreceptors.
D015107:4-Butyrolactone / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002421:Caudate Nucleus / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D005663:Furans / Q000494:pharmacology*; D006220:Haloperidol / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011954:Receptors, Dopamine / Q000187:drug effects*
D005663:Furans; D011954:Receptors, Dopamine; D006220:Haloperidol; D015107:4-Butyrolactone; D004298:Dopamine