The resting potential of moth muscle fibre

摘要: 1. The membrane of the moth muscle fibre was tested for resting permeability to various ions: it is not permeable Mg(2+) or Ca(2+); slightly Na(+) and NH(4) (+); appreciably Cl(-), but Cl(-) passively distributed; apparently H(+) effects HCO(3) (-) are ruled out; primarily K(+).2. Measurement internal K(+) activity showed that E(K) less negative than potential.3. In presence DNP, under anoxia, potential approaches, E(K); there a small concomitant decrease in effective resistance.4. An increase external Ca(2+) concentration accompanied by increased resistance an amplitude potential.5. Cooling (below room temperature) decreased 4-16 mV per 10 degrees C, large resistance.6. experimental results most readily fit hypothesis fibre, although highly K(+), H(+), maintained electrogenic transport process which generates ionic current across membrane. possibility gradient ions metabolically at level sufficient explain considered be unlikely could directly excluded.