The Na~+/Ca~(2+) Exchanger Isoform 3 (NCX3) but Not Isoform 2 (NCX2) and 1 (NCX1) Singly Transfected in BHK Cells Plays a Protective Role in a Model of in Vitro Hypoxia

摘要

Chemical hypoxia produces depletion of ATP, intracellular Ca~(2+) overload, and cell death. The role of Na~+/Ca~(2+) exchanger (NCX), the major plasma membrane Ca~(2+) extruding system, has been explored in chemical hypoxia using BHK cells stably transfected with the three mammalian NCX isoforms: NCX1, NCX2, and NCX3. Here we report that the three isoforms show similar activity evaluated as [Ca~(2+) ]_i increase evoked by Na~+-free medium exposure in Fura-2-loaded single cells and NCX3 transfected cells are less vulnerable to chemical hypoxia compared to NCX1- and NCX2-transfected cells, suggesting that NCX3 could play a more relevant protective role during chemical hypoxia.