The naphthalenesulphonamide calmodulin antagonist W7 and its 5-iodo-1-C8 analogue inhibit potassium and calcium currents in NG108-15 neuroblastoma x glioma cells in a manner possibly unrelated to their antagonism of calmodulin

• Published in: Neuroscience letters Vol. 125; no. 1; p. 57
• Main Authors: Caulfield, M P, Robbins, J, Sim, J A, Brown, D A, Mac Neil, S, Blackburn, G M
• Format: Journal Article
• Language: English
• Published: Ireland 15.04.1991
• Subjects: Animals; Calcium Channels - drug effects; Calcium Channels - physiology; Calmodulin - antagonists & inhibitors; Cell Line; Evoked Potentials - drug effects; Glioma; Hybrid Cells - drug effects; Hybrid Cells - physiology; Kinetics; Membrane Potentials - drug effects; Neuroblastoma; Potassium Channels - drug effects; Potassium Channels - physiology; Sulfonamides - pharmacology
• ISSN: 0304-3940
• DOI: 10.1016/0304-3940(91)90130-L

Patch clamp techniques were used to record voltage-sensitive calcium and potassium currents from NG108-15 cells. N-(6-aminohexyl)-5-chloro-1-naphthalene- sulphonamide (W7), a calmodulin (CaM) antagonist and its more potent (10 times) 5-iodo-1-C8 analogue (J8) inhibited these currents in a dose-dependent manner. The inhibition was not dependent on internal or external Ca2+. W7 was about four times more potent as an inhibitor of the transient potassium current (IC50 = 8 microM) than of the M-current or of the calcium current. J8 was also selective for the potassium currents (IC50 values: transient current 4 microM, M-current 11 microM) compared to the calcium current (IC50 36 microM). It is suggested that the inhibition does not result from an anti-CaM action of the compounds.