Kinetic analysis of GM1 effects on haloperidol-induced dopaminergic supersensitivity.
The relative affinity of metoclopramide as indicated by K(B) values was calculated in control and in haloperidol-withdrawn rats treated or not with monosialoganglioside-1 (GM1) by using dose-response curves constructed for apomorphine-induced stereotyped behavior. Haloperidol withdrawal decreased K(B) data--that is, increased the D2-receptor affinity for metoclopramide. GM1 treatment per se did not modify K(B) values but, when given in combination with haloperidol, GM1 induced a decrease in K(B) values. No differences were found in K(B) data when GM1 was administered after withdrawal from haloperidol.
Palermo-Neto
J
J
Applied Pharmacology and Toxicology Laboratory, School of Veterinary Medicine, University of São Paulo, Brazil. j.palermo@usp.br
Frussa-Filho
R
R
Vital
M A
MA
D000818:Animals; D018492:Dopamine Antagonists / Q000494:pharmacology*; D005677:G(M1) Ganglioside / Q000494:pharmacology*; D006220:Haloperidol / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D013239:Stereotyped Behavior / Q000187:drug effects
D018492:Dopamine Antagonists; D017448:Receptors, Dopamine D2; D005677:G(M1) Ganglioside; D006220:Haloperidol