Intracellular calcium concentrations during metabolic inhibition in the motoneuron cell line NSC-19

Can J Physiol Pharmacol. 1994 Jul;72(7):728-37. doi: 10.1139/y94-104.


Changes in the concentrations of intracellular free calcium ([Ca2+]i) and adenine nucleotides were determined in response to metabolic inhibitors in the motoneuron cell line NSC-19. The NADH dehydrogenase inhibitor amobarbital (Amytal) and the mitochondrial uncoupler carbonylcyanide m-chlorophenylhydrazone (CCCP) were used to alter energy metabolism. Exposure of cells to 5 mM Amytal did not significantly change ATP concentrations but produced transient elevations of [Ca2+]i of approximately 80 nM, which were reduced by 32% when cells were studied in Ca(2+)-free solutions. CCCP (10 microM) caused a transient reduction in ATP concentration of 33%. CCCP also produced sustained elevations of [Ca2+]i of about 280 nM, which were reduced by 47% when in Ca(2+)-free solutions. In spite of the sustained elevation of [Ca2+]i induced by CCCP, NSC-19 showed no reduction in cell viability after 48 h compared with controls. Ruthenium red, a blocker of Ca2+ uptake by mitochondria, had little effect on the CCCP-induced [Ca2+]i increment. KCl or glutamate did not produce significant changes in [Ca2+]i, indicating that these cells do not possess significant numbers of voltage-dependent Ca2+ channels or excitatory amino acid receptor-gated channels. [Ca2+]i values in these cells were modified by changes in extracellular Ca2+ concentrations. In Ca(2+)-containing solutions, inhibition of Na+/Ca2+ exchange by amiloride and bepridil led to increased [Ca2+]i, as did blockade of Ca2+ ATPase by vanadate, suggesting that membrane transporters are important in Ca2+ efflux in NSC-19. The present studies indicate that exposure of NSC-19 cells to Amytal and CCCP produces Ca2+ increments by release from internal stores, as well as by transmembrane influx. These results demonstrate that small increments in [Ca2+]i can be produced by metabolic inhibitors or other compounds and that such changes are not associated with immediate cell death. Changes in [Ca2+]i could potentially result in abnormal cell function secondary to altered action of Ca(2+)-dependent enzymes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenine Nucleotides / metabolism
  • Adenosine Triphosphatases / antagonists & inhibitors
  • Amobarbital / pharmacology
  • Animals
  • Antimetabolites / pharmacology*
  • Calcium / metabolism*
  • Calcium / pharmacology
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone / pharmacology
  • Carrier Proteins / antagonists & inhibitors
  • Carrier Proteins / metabolism
  • Cell Line
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Cell Survival / drug effects
  • Cytosol / drug effects
  • Cytosol / metabolism
  • Energy Metabolism / drug effects
  • Hybrid Cells
  • Mice
  • Microscopy, Fluorescence
  • Motor Neurons / drug effects
  • Motor Neurons / metabolism*
  • Sodium / metabolism
  • Sodium-Calcium Exchanger
  • Vanadates / pharmacology


  • Adenine Nucleotides
  • Antimetabolites
  • Carrier Proteins
  • Sodium-Calcium Exchanger
  • Vanadates
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone
  • Sodium
  • Adenosine Triphosphatases
  • Amobarbital
  • Calcium