Related Experiment Video
Updated: Aug 30, 2026

Mechanical Stimulation-induced Calcium Wave Propagation in Cell Monolayers: The Example of Bovine Corneal Endothelial Cells
Published on: July 16, 2013
Pardaxin-stimulated calcium uptake in PC12 cells is blocked by cadmium and is not mediated by L-type calcium channels
B Nikodijevic1, D Nikodijevic, P Lazarovici
1Section on Growth Factors, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892.
Abstract:
Pardaxin is an excitatory neurotoxin which triggers neurotransmitter release as a result of voltage-dependent pore formation within the neuronal membrane. We have used several pharmacological manipulations of calcium influx to characterize pardaxin pore activity in PC12 cells in culture. Pardaxin stimulates the uptake of radioactive calcium into PC12 cells in a dose dependent fashion (ED50 of 0.4 microM). This stimulation is partially inhibited by nifedipine, a blocker of L-type calcium channels. Effective blockade of pardaxin stimulation was produced by the inorganic calcium channel blockers cadmium (IC50 of 10 microM) and nickel (2 mM). Homologous down regulation of L-calcium channels by the agonist Bay K-8644, inhibited the subsequent stimulation of calcium uptake by this drug, but not by pardaxin. A fluorometric analysis of pardaxin pore formation in unilamellar large liposomes indicates pardaxin pores are blocked by cadmium (10-200 microM). These data distinguish between pardaxin pores and L-type calcium channels in PC12 cells. We suggest pardaxin as a pharmacological ionophore tool to modulate neuronal calcium homeostasis and neurotransmitter release.
Related Concept Videos
G-Protein Gated Ion Channels
Sensory organs,...
GPCRs Regulate Adenylyl Cylase Activity
Two...
IP3/DAG Signaling Pathway
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Ligand-Gated Ion Channel Receptor: Gating Mechanism

