The reverse mode of the Na⁺/Ca²⁺ exchanger provides a source of Ca²⁺ for store refilling following agonist-induced Ca²⁺ mobilization

Abstract

Hirota S, Pertens E, Janssen LJ. The reverse mode of the Na ϩ /Ca 2ϩ exchanger provides a source of Ca 2ϩ for store refilling following agonist-induced Ca 2ϩ mobilization.

The Role of Sodium-Calcium Exchanger in the Calcium Homeostasis of Airway Smooth Muscle

“…Our group reported [35] that the tonic phase of the contraction induced by histamine is partially blocked by KB-R7943 and its effect is not due to the Ca 2+ voltage dependent channel blockage since these had been previously inhibited by Nifedipine. Other groups have reported similar results to ours [116][117][118]. Therefore, it is expected that in the next years different research groups will proceed to investigate if NCX blockers have any kind of therapeutic use in animal Asthma models.…”

“…Hirota et al [98] have also suggested a functional association between the NCX and TRPC activated by store depletion in dog ASM. In that work, several agonists were tested on tracheal rings together with NCX inhibitor KB-R7943 and sensitivity to this drug was observed.…”

Airway smooth muscle dynamics: a common pathway of airway obstruction in asthma

“…Ca 2+ influx can also be influenced by the contractile agonist indicating either activation of receptor-operated channels or a second messenger-operated channel. In addition, the occurrence of Ca 2+ -dependent nonspecific cation currents can lead to increased intracellular Na + and the reversal of Na + /Ca 2+ exchanger to increase Ca 2+ entry [276]. Clearly, ASM cells are well equipped with multiple Ca 2+ import pathways to ensure store refilling.…”

Maintenance Of Calcium Homeostasis in Embryonic Stem Cell-Derived Cardiomyocytes

“…Ca 2+ influx via the reverse mode of NCX has been suggested to act synergistically with Ca 2+ influx via L-type Ca 2+ channels to trigger Ca 2+ release from the SR as I Ca, L are small at depolarized membrane potential (Sah et al, 2003). In addition, NCX can positively regulate SR Ca 2+ load via the reverse mode action (Hirota et al, 2007). Interestingly, under pathophysiological conditions such as cardiac failure, NCX also operates in the reverse mode to allow additional Ca 2+ influx for contraction in order to compensate for the reduction in Ca 2+ release from SR (Gaughan et al, 1999).…”