palytoxin and sodium-binding-benzofuran-isophthalate

Palytoxin was found to equilibrate sodium ions (Na+) across the cell membrane much faster than dose gramicidin, which has been frequently used to calibrate the intracellular Na+ concentration ([Na+]in), in cells treated with a Na+-sensitive fluorescent dye, sodium-binding benzofuran isophthalate (SBFI). Palytoxin was capable of equilibrating Na+ in cells treated with SBFI-acetoxymethyl ester (SBFI-AM) and in voltage-clamped cells loaded with SBFI through a patch pipette. Nicotine caused a dose-dependent increase in ([Na+]in) in porcine adrenal chromaffin cells treated with SBFI-AM and caused a simultaneous increase in [Na+]in and inward current in the voltage-clamped cells loaded with SBFI. Palytoxin has an advantage of calibrating ([Na+]in) in a shorter time than dose gramicidin because of its powerful ionophoretic activity.

Topics: Acrylamides; Animals; Benzofurans; Calibration; Cells, Cultured; Chromaffin Cells; Cnidarian Venoms; Dialysis; Drug Evaluation, Preclinical; Ethers, Cyclic; Fluorescent Dyes; Gramicidin; Ionophores; Membrane Potentials; Nicotine; Patch-Clamp Techniques; Sodium; Swine