Mehmet KURT, Süleyman ÇELİK, Yüksel KESİM

Motor eşgüdümde dopaminerjik sistemin rolü

Yapılan çalışmalar santral sinir sisteminde depaminerjik aktiviteyi artıran ilaçların motor aktiviteyi artırdığını göstermiştir. Bu çalışmada motor eşgüdümde dopamin reseptörlerinin rolü döner-çubuk dayanıklılık (rotarod performans) yöntemi ile araştırılmıştır. Seçici olmayan dopamin agonisti apomorfin, sıçanların rotarod performansını düşük dozlarda (0.125 - 0.25 mg/kg) azaltmış, yüksek dozlarda (0.5-1 mg/kg) ise artırmıştır. Apornorfin ile oluşan rotarod performans artışı seçici olmayan DA antagonisti flufenazin (0.125 mg/ kg), seçici D2 antagonistleri sulpirid (50 mg/kg) ve spiperon (40 ug/kg ) ile önlenmiştir. Seçici D1 agonisti SKF 81297 (10 mg/kg) rotarod performansı anlamlı olarak artırmış ve bu artış flufenazin (0.125 mg/kg) ile önlenmiştir. Seçici D2 agonisti bromokriptin (5. 10. 20, 30 mg/kg) rotarod performansı artırmış ve bu artışlar seçici D2 antagonisti sulpirid (50 mg/kg) ve dopamin sentez inhibitörü alfa-metil p-tirozin ile önlenmiştir. Bu çalışmanın bulguları hem D1 hem de D2 dopamin reseptörlerinin motor eşgüdümde rol oynayabileceğini göstermektedir

Anahtar Kelimeler:

Reseptörler, dopamin D1, Reseptörler, dopamin D2, Modeller, hayvan, Modeller, teorik, Sıçanlar, Apomorfin, Dopamin antogonistleri, Sülpirid, Bromokriptin, Motor aktivite

The role of dopaminergic system in motor coordination

Previous studies have demonstrated that dopamine (DA) receptor agonists enhanced locomotor activity. The present study was designed to determine the relative contribution OfD1 and D2 (DA) receptor subtypes in motor coordination. Apomorphlne, a nonselective dopamine receptor agonist, decreased motor coordination at the doses of 0.125 and 0.25 mg/kg, but increased the motor coordination at 0.5 and 1 mg/kg. The D2 dopamine receptor antagonists, sulpiride (50 mg/kg) and spiperone (40 ug/kg), decreased motor coordination when administrered either alone or combination with apomorphine (0.5 mg/kg). Selective D1 receptor agonist SKF 81297 (10 mg/kg) enhanced motor coordination. The effect of SKF 81297 was antagonized by fluphenazine (0.125 mg/kg). The D2 receptor agonist bromocriptine (5, 10, 20, 30 mg/kg) significantly increased motor coordination. The effect of bromocriptine (10 mg/kg) was inhibited when administered either sulpirid (50 mg/kg) or alpha-methyl p-tyroslne prior to bromocriptine. These data demonstrated that both D1 and D2 receptors may involved in motor coordination.

Keywords:

Receptors, Dopamine D1, Receptors, Dopamine D2, Models, Animal, Models, Theoretical, Rats, Apomorphine, Dopamine Antagonists, Sulpiride, Bromocriptine, Motor Activity,

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