Adult rat cardiomyocytes exhibit capacitative calcium entry Export

@article{citeulike:4015128, abstract = {Capacitative Ca2+ entry (CCE) refers to the influx of Ca2+ through plasma membrane channels activated on depletion of endoplasmic-sarcoplasmic reticulum Ca2+ stores. We utilized two Ca2+-sensitive dyes (one monitoring cytoplasmic free Ca2+ and the other free Ca2+ within the sarcoplasmic reticulum) to determine whether adult rat ventricular myocytes exhibit CCE. Treatments with inhibitors of the sarcoplasmic endoplasmic reticulum Ca2+-ATPases were not efficient in releasing Ca2+ from stores. However, when these inhibitors were coupled with either Ca2+ ionophores or angiotensin II (an agonist generating inositol 1,4,5 trisphosphate), depletion of stores was observed. This depletion was accompanied by a significant influx of extracellular Ca2+ characteristic of CCE. CCE was also observed when stores were depleted with caffeine. This influx of Ca2+ was sensitive to four inhibitors of CCE (glucosamine, lanthanum, gadolinium, and SKF-96365) but not to inhibitors of L-type channels or the Na+/Ca2+ exchanger. In the whole cell configuration, an inward current of [\~{}]0.7 pA/pF at -90 mV was activated when a Ca2+ chelator or inositol (1,4,5)-trisphosphate was included in the pipette or when Ca2+ stores were depleted with a Ca2+-ATPase inhibitor and ionophore. The current was maximal at hyperpolarizing voltages and inwardly rectified. The channel was relatively permeant to Ca2+ and Ba2+ but only poorly to Mg2+ or Mn2+. Taken together, these data support the existence of CCE in adult cardiomyocytes, a finding with likely implications to physiological responses to phospholipase C-generating agonists. 10.1152/ajpheart.00162.2003}, author = {Hunton, Dacia L. and Zou, Luyun and Pang, Yi and Marchase, Richard B.}, citeulike-article-id = {4015128}, citeulike-linkout-0 = {http://dx.doi.org/10.1152/ajpheart.00162.2003}, citeulike-linkout-1 = {http://ajpheart.physiology.org/cgi/content/abstract/286/3/H1124}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/14630640}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=14630640}, day = {1}, doi = {10.1152/ajpheart.00162.2003}, journal = {Am J Physiol Heart Circ Physiol}, keywords = {capacitive-calcium-entry, mag-fluo-4, rat, ventricular-myocytes}, month = {March}, number = {3}, pages = {H1124--1132}, posted-at = {2009-02-07 02:49:53}, priority = {0}, title = {Adult rat cardiomyocytes exhibit capacitative calcium entry}, url = {http://dx.doi.org/10.1152/ajpheart.00162.2003}, volume = {286}, year = {2004} }

TY - JOUR ID - citeulike:4015128 L3 - citeulike-article-id:4015128 N2 - Capacitative Ca2+ entry (CCE) refers to the influx of Ca2+ through plasma membrane channels activated on depletion of endoplasmic-sarcoplasmic reticulum Ca2+ stores. We utilized two Ca2+-sensitive dyes (one monitoring cytoplasmic free Ca2+ and the other free Ca2+ within the sarcoplasmic reticulum) to determine whether adult rat ventricular myocytes exhibit CCE. Treatments with inhibitors of the sarcoplasmic endoplasmic reticulum Ca2+-ATPases were not efficient in releasing Ca2+ from stores. However, when these inhibitors were coupled with either Ca2+ ionophores or angiotensin II (an agonist generating inositol 1,4,5 trisphosphate), depletion of stores was observed. This depletion was accompanied by a significant influx of extracellular Ca2+ characteristic of CCE. CCE was also observed when stores were depleted with caffeine. This influx of Ca2+ was sensitive to four inhibitors of CCE (glucosamine, lanthanum, gadolinium, and SKF-96365) but not to inhibitors of L-type channels or the Na+/Ca2+ exchanger. In the whole cell configuration, an inward current of [~]0.7 pA/pF at -90 mV was activated when a Ca2+ chelator or inositol (1,4,5)-trisphosphate was included in the pipette or when Ca2+ stores were depleted with a Ca2+-ATPase inhibitor and ionophore. The current was maximal at hyperpolarizing voltages and inwardly rectified. The channel was relatively permeant to Ca2+ and Ba2+ but only poorly to Mg2+ or Mn2+. Taken together, these data support the existence of CCE in adult cardiomyocytes, a finding with likely implications to physiological responses to phospholipase C-generating agonists. 10.1152/ajpheart.00162.2003 IS - 3 JF - Am J Physiol Heart Circ Physiol EP - 1132 TI - Adult rat cardiomyocytes exhibit capacitative calcium entry VL - 286 SP - H1124 KW - capacitive-calcium-entry KW - mag-fluo-4 KW - rat KW - ventricular-myocytes AU - Hunton, Dacia AU - Zou, Luyun AU - Pang, Yi AU - Marchase, Richard PY - 2004/03/01/ UR - http://dx.doi.org/10.1152/ajpheart.00162.2003 ER -