Effect of temperature on spontaneous Ca2+-activated CI− currents in rabbit portal vein cells
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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° C and 35° C. The time constant of the decay (τ) was decreased with increasing temperature and had a temperature coefficient, Q10, of 2.6. The temperature sensitivity of τ could be described by the Arrhenius equation which gave an activation energy of 16 kcal/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.
Key wordsSmooth muscle Ca2+-activated Cl− current Temperature
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