Effect of temperature on the inward rectifier and gramicidin A-induced channels in the membrane of frog skeletal muscle fibres

Abstract

The conductance of frog skeletal muscle fibres in isotonic K2SO4 solution has been measured. Experiments were carried out under current-clamp conditions using a double sucrose-gap technique. The potassium conductances of the inward rectifier and the gramicidin channel in the same muscle fibre were compared. Potassium conductance of the inward rectifier increased with the temperature, with a value of Q10 1.55 +/- 0.09 (n = 8) under hyperpolarization, and Q10 2.38 +/- 0.23 (n = 6) for the depolarizing stimulus, the difference between Q10 of potassium and gramicidin channels being statistically insignificant.