[3H]YM-09151-2 (nemonapride), a potent radioligand for both sigma 1 and sigma 2 receptor subtypes.
Using K+ phosphate buffer with 25 nM spiperone, [3H]YM-09151-2 binding showed a high affinity for sigma receptors but no affinity for D2 dopamine or 5-HT1A receptors in rat brain. The order of pKi values of various sigma compounds at [3H]YM-09151-2 binding sites and stereoisomer selectivity were consistent with previous studies using other sigma ligands such as (+)-[3H]SKF-10047, [3H]DTG and (+)-[3H]3-PPP. Although Scatchard analysis fitted a one-site model, competition between [3H]YM-09151-2 and (+)-pentazocine revealed two sites, sigma 1 and sigma 2 receptors, at which the Ki values of YM-09151-2 were 8.4 nM and 9.6nM, respectively. Autoradiography using [3H]YM-09151-2 also showed a characteristic distribution of sigma receptors in rat brain. [3H]YM-09151-2 is, therefore, a potent and useful radioligand for sigma 1/sigma 2 receptor subtypes.
Ujike
H
H
Department of Neuropsychiatry, Okayama University Medical School, Japan.
Akiyama
K
K
Kuroda
S
S
D000818:Animals; D001345:Autoradiography; D001549:Benzamides / Q000378:metabolism*; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D017480:Receptors, sigma / Q000187:drug effects / Q000378:metabolism*; D013223:Statistics as Topic; D013237:Stereoisomerism; D014316:Tritium
D001549:Benzamides; D018492:Dopamine Antagonists; D017480:Receptors, sigma; D014316:Tritium; C030265:nemonapride