Co-expression of mCysLT_1 receptors and IK channels in Xenopus laevis oocytes elicits LTD_4-stimulated IK current, independent of an increase in [Ca~(2+)]_i

摘要

Addition of LTD_4 (10 nM) to Xenopus laevis oocytes expressing the mCysLT_1 receptor together with hBK or hIK channels resulted in the activation of both channels secondary to an LTD_4-induced increase in [Ca~(2+)]_i. In addition, the hIK channel is activated by low concentrations of LTD_4 (<0.1 nM), which did not result in any increase in [Ca~(2+)]_i. Even though activation of hIK by low concentrations of LTD4 was independent of an increase in [Ca~(2+)]_i, a certain "permissive" level of [Ca~(2+)]_i was required for its activation, since buffering of intracellular Ca~(2+) by EGTA completely abolished the response to LTD_4. Neither hTBAK1 nor hTASK2 was activated following stimulations with LTD_4 (0.1 and 100 nM).