Rotigotine (N-0923) is a non-ergot dopamine receptor agonist used in the therapy of Parkinson disease and restless leg syndrome. Administered as a once-daily transdermal patch, Rotigotine has not been associated with serum enzyme elevations during treatment or with episodes of clinically apparent liver injury.

D5 receptor:4-15 nM (Ki), D2 receptor:4-15 nM (Ki), 5-HT1A receptor:30 nM (Ki), D3 receptor:0.71 nM (Ki), D4 receptor:4-15 nM (Ki), D1 receptor:83 nM (Ki), 5-HT7 receptor:86 nM (Ki)

The selectivity of Rotigotine for D3 (pKi 9.2) receptors is higher 10-fold than D2/D4/D5 (pKi 8.5-8.0) and 100-fold than D1 receptors (pKi 7.2). Rotigotine (10 μM) decreases the number of THir neurons by 40% in primary mesencephalic cell culture. In functional studies, Rotigotine behaves as a full agonist at all dopamine receptors but notably, the potency for stimulation of D1 receptors is similar to that for D2/D3 receptors (pEC50 respectively: 9.0, 9.4-8.6, 9.7). Rotigotine (0.01 μM) slightly protects dopaminergic neurons against MPP+ toxicity, significantly protects dopaminergic neurons against rotenone-induced cell death, and significantly inhibits ROS production by rotenone.

In primed rats, Rotigotine (0.035/0.1/0.35 mg/kg) dose-dependently induces contralateral turning behavior. In drug-naive rats, the turning behavior induced by Rotigotine, either alone or in combination with SCH 39166, is reduced compared to primed rats.

Binding assays are performed in 96-well polypropylene tubes in a final volume of 2?mL for D1 and D4 membranes and 1?mL for D2, D3 and D5 membranes containing: 50?μL radioligand, 10?μL drug/buffer/non-specific binding, buffer (final concentration 50?mM Tris-HCl pH 7.4, MgCl2 2?mM) and membranes (5?μg protein for D2 and D3 and 25?μg protein for D1 and D5). Following 120?min of incubation at 25°C, bound radioligand is determined by rapid vacuum filtration through A/C glass fibre filters presoaked in 0.1% polyethylenimine. The filters are washed four times with 2?mL ice-cold ishing buffer (Tris-HCl 50?mM, pH?7.4 at 4°C) and retained radioactivity is determined by liquid scintillation counting.