Electrophysiological Membrane Properties of the Frog Muscle Fibre: Effects of Detergents in the Triton Series

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Abstract
The effect of the nonionic detergent Triton X-100 on membrane properties of frog sartorius muscle fibers was studied using intracellular microelectrode technique. The effect of Triton X-100 was compared with that of Triton X-45 and Triton N-101. At 40 .mu.M Triton X-100 had little effect on specific membrane resistance, membrane capacitance and resting membrane potential (Er), while the action potential (AP) was markedly reduced. At 160 .mu.M AP was completely abolished and Er was diminished linearly with time. The effect on maximum rate of rise of the AP was dose-dependent and the apparent dissociation constant and KD apparently were about 40 .mu.M. The Hill coefficient was 1.6 indicating a deviation from a 1st order reaction. The effect of Triton X-100 on Er may be accounted for by a reduction of the Na-K pumping activity. The effect of Triton X-100 on the AP may be due to a perturbation of a protein-system either by a drug-receptor interaction involving 2 or more sites or an unspecific binding of Triton X-100 to hydrophobic loci on the protein.