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

Brain Res. 2005 Jul 5;1049(1):80-8. doi: 10.1016/j.brainres.2005.04.073.

Abstract

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 microM Ipt significantly protected cells against neurotoxin-induced glutamate uptake diminishment, and this protection was abolished by the K(ATP) channel blocker glibenclamide (20 microM), 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 microM 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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport System X-AG / drug effects*
  • Amino Acid Transport System X-AG / metabolism
  • Animals
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / metabolism
  • Disease Models, Animal
  • Glutamic Acid / drug effects
  • Glutamic Acid / metabolism
  • Male
  • Neostriatum / drug effects
  • Neostriatum / metabolism
  • Neuroprotective Agents / pharmacology*
  • Neuroprotective Agents / therapeutic use
  • Neurotoxins / pharmacology
  • PC12 Cells
  • Parkinsonian Disorders / drug therapy*
  • Potassium Channels / drug effects*
  • Potassium Channels / metabolism
  • Propylamines / pharmacology*
  • Propylamines / therapeutic use
  • Rats
  • Rats, Sprague-Dawley
  • Synaptosomes / drug effects*
  • Synaptosomes / metabolism

Substances

  • Amino Acid Transport System X-AG
  • N-(1-methylethyl)-1,1,2-trimethylpropylamine
  • Neuroprotective Agents
  • Neurotoxins
  • Potassium Channels
  • Propylamines
  • Glutamic Acid