Iptakalim hydrochloride protects cells against neurotoxin-induced glutamate transporter dysfunction in in vitro and in vivo models

Iptakalim hydrochloride (Ipt), a novel antihypertensive drug, exhibits K_ATP channel activation. Here, we report that Ipt remarkably protects cells against neurotoxin-induced glutamate transporter dysfunction in in vitro and in vivo models. Chronic exposure of cultured PC12 cells to neurotoxins, such as 6-OHDA, MPP⁺, or rotenone, decreased overall [ ³H]-glutamate uptake in a concentration-dependent manner. Pre-treatment using 10 μM Ipt significantly protected cells against neurotoxin-induced glutamate uptake diminishment, and this protection was abolished by the K_ATP channel blocker glibenclamide (20 μM), suggesting that the protective mechanisms may involve the opening of K _ATP channels. In 6-OHDA-treated rats (as an in vivo Parkinson's disease model), [³H]-glutamate uptake was significantly lower in synaptosomes isolated from the striatum and cerebral cortex, but not the hippocampus. Pre-conditioning using 10, 50, and 100 μM Ipt significantly restored glutamate uptake impairment and these protections were abolished by blockade of K_ATP channels. It is concluded that Ipt exhibits substantial protection of cells against neurotoxicity in in vitro and in vivo models. The cellular mechanisms of this protective effect may involve the opening of K_ATP channels. Collectively, Ipt may serve as a novel and effective drug for PD therapy.