Properties of voltage-gated Na+ channels in the human rhabdomyosarcoma cell-line SJ-RH30: conventional and automated patch clamp analysis.

摘要: Abstract Conventional and automated patch clamp electrophysiology were used to characterise the Na + current of SJ-RH30 human rhabdomyosarcoma. In conventional recordings cells exhibited a fast activating, inactivating at potentials positive −40 mV; in full current–voltage curves maximum occurred between −20 −10 mV. Inactivation kinetics 0 mV biexponential with time constants 0.5 3.7 ms. Deinactivation −90 mV also two kinetic components. Tetrodotoxin (TTX) blocked completely 1 μM. The V 1.4 selective toxin μ-CTx-GIIIB reversibly ∼60% 10 μM. Very similar biophysical behaviour was observed recordings. For example, inactivation mid-point −72 ± 2 mV (slope factor 7.2 ± 0.2) −74 ± 2 mV 7.4 ± 0.4) recording. corresponding values for activation −33.2 ± 2.4 −30.3 ± 2.7 mV 5.8 ± 0.3 6.4 ± 0.3, respectively). throughput method generate additional pharmacological data on inhibition current. TTX inhibited an IC 50 23 nM. channel concentration-dependent manner. Inhibition produced by both tetracaine amitriptyline shown be frequency-dependent. Our experiments indicate that arises mainly from channels phenotype like recombinant channels. suitability these suggests they may useful higher studies interaction drugs skeletal muscle