Effect of temperature on spontaneous Ca2+-activated Cl- currents in rabbit portal vein cells.

The effect of temperature on the time course of spontaneous transient inward (Ca2+-activated Cl-) currents (STICs) was investigated with the perforated patch technique in rabbit portal vein cells. STICs decayed exponentially at temperatures between 17 degrees C and 35 degrees C. The time constant of the decay (tau ) was decreased with increasing temperature and had a temperature coefficient, Q10, of 2.6. The temperature sensitivity of tau could be described by the Arrhenius equation which gave an activation energy of 16kcal/mol. This result indicates that STIC decay is governed by a single first-order reaction and provides further support for the hypothesis that the decay is due to the gating properties of Ca2+-activated Cl- channels.