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Noradrenaline-Induced Inhibition of Voltage-Sensitive Calcium Currents in NG108-15 Hybrid Cells


R. J. Docherty, as above.


The effect of noradrenaline (NA) on voltage-sensitive calcium currents in neuroblastoma × glioma hybrid (NG108-15) cells has been studied using a whole-cell clamp technique. NA inhibited calcium current. The EC50 for NA induced inhibition was 177 nM. The NA receptor involved had a similar pharmacological profile to α2 adrenoreceptors but did not respond to clonidine. NA inhibited calcium current by an amount which depended on both membrane potential and current amplitude. When current-dependent inactivation of calcium current was maximal, NA was without effect. The data are consistent with a mechanism where NA enhances current-dependent inactivation.