SKF89976A hydrochloride (d,l-SKF89976A hydrochloride) is a selective inhibitor GABA transporter such as GAT-1 (IC50s = 0.28 μM), GAT-2 (IC50s = 137.34 μM) and GAT-3(IC50s = 202.8 μM) in CHO cells.

GAT-1:137.34 μM , GAT-3:202.8 μM , GAT-1:0.28 μM

SKF89976A exhibits weak antiallodynic properties and mildly inhibits the serotonin transporter (SERT), noradrenaline transporter (NET), and dopamine transporter (DAT) in Chinese hamster ovary (CHO) cells that stably express these transporters, as demonstrated in substrate uptake assays with IC50 values of 3514, 202.13, and 728.8, respectively. Additionally, SKF89976A functions as a GABA-transport blocker, effectively suppressing GABA-induced inward currents in the presence of GABA transport inhibitors tiagabine and SKF89976A at specified concentrations, while remaining unaffected by picrotoxin. Remarkably, SKF89976A, at a concentration of 100 μM, can reversibly block GABA transport into cells, thus eliminating GABA-elicited currents. It further acts as a non-transportable blocker of GAT-1, reducing baseline inward currents likely due to tonic GAT activation by background GABA. At a concentration of 100 μM, SKF89976A was able to reversibly reduce GAT currents by 67.9±4.4% in all studied cells (n=19), and a 20 μM intracellular perfusion of SKF89976-A progressively diminished and blocked GABA-induced GAT currents without affecting GABAAR-mediated currents.

When administered i.v. (0.3 mg/kg), SKF89976A produces a weak antiallodynic response . The i.t. injection of SKF89976A dose-dependently ameliorates the reduction in the withdrawal threshold in PSL model mice[1].