Melatonin administration increases the affinity of D2 dopamine receptors in the rat striatum.
Rats receive melatonin (MEL) (476 +/- 6.5 microg/kg/day) via their drinking water for 2 weeks. At the end of this period, the density of D2 dopamine (DA) receptors and their affinity for [3H]-YM-09151-2 are measured in the striatum. MEL treatment increases the apparent affinity (decreases the Kd) of D2 DA receptors for [3H]YM-09151-2 by 48%, while it does not significantly alter the density (Bmax). These findings indicate that the affinity of D2 DA receptors in the striatum is influenced by exposure to MEL. The possible implications of these results are discussed.
Hamdi
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A
Department of Clinical Pharmacology, King Saud University, College of Medicine ABHA, Saudi Arabia.
D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D001835:Body Weight / Q000187:drug effects; D018492:Dopamine Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D008550:Melatonin / Q000494:pharmacology / Q000502:physiology*; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000378:metabolism*
D001549:Benzamides; D018492:Dopamine Antagonists; D017448:Receptors, Dopamine D2; D008550:Melatonin; C030265:nemonapride