Behavioural motor effects of MK-801 and DNQX parenteral administration in adult cats: dose-response analysis. Modulatory role of dopaminergic D1 and D2 antagonists on MK-801 induced motor behaviours.
1. Administration of MK-801 a selective antagonist of the NMDA receptors (50, 100 and 150 micrograms/kg, s.c.) elicited in adult cats ataxia and loss of equilibrium. A dose-response effect was observed. 2. Administration of DNQX, a selective antagonist of the non-NMDA receptors, even with doses 20 times higher than those employed with MK-801, did not produce any behavioural disturbances. 3. Previous injection of SCH 23390, a selective parenteral antagonist of dopamine D1 receptor, reduced significantly the intense ataxic effects of MK-801, while sulpiride only increased the latency of the symptoms. 4. The results are discussed considering the reported interactions between the dopaminergic and glutamatergic systems.
Motles
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E
Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 9, Chile.
Infante
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C
Gonzalez
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M
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001552:Benzazepines / Q000494:pharmacology; D002415:Cats; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000494:pharmacology; D065127:Dopamine D2 Receptor Antagonists; D004305:Dose-Response Relationship, Drug; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D005260:Female; D007279:Injections, Subcutaneous; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D016202:N-Methylaspartate / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology*; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors*; D013469:Sulpiride / Q000494:pharmacology
D001552:Benzazepines; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D011810:Quinoxalines; D017447:Receptors, Dopamine D1; C056723:FG 9041; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D013469:Sulpiride