Elevation of cytoplasmic Ca2+ levels in human erythrocytes induces a progressive loss of membrane phospholipid asymmetry, a process that is impaired in erythrocytes from a patient with Scott syndrome. We show here that porcine erythrocytes are similarly incapable of Ca2'-induced redistribution of membrane phospholipids. Because a complex of phosphatidylinositol 4.5-bisphosphate (PIP,) and Ca2+ ...

Antisense oligodeoxynucleotides (AS-oligos) targeted to the Na+/Ca2+exchanger (NCX) inhibit NCX-mediated Ca2+ influx in mesenteric artery (MA) myocytes [ Am. J. Physiol.269 ( Cell Physiol. 38): C1340-C1345, 1995]. Here, we show AS-oligo knockdown of NCX-mediated Ca2+ efflux. In initial experiments, the cytosolic free Ca2+ concentration ([Ca2+]cyt) was raised, and sarcoplasmic reticulum (SR) Ca2...

ERcalcistorin/protein-disulfide isomerase (ECaSt/PDI), a high capacity low affinity Ca2+-binding protein in the endoplasmic reticulum of sea urchin eggs (Lebeche, D., and Kaminer, B. (1992) Biochem. J. 287, 741-747), shares 55% sequence identity with mammalian PDI and has PDI activity (Lucero, H., Lebeche, D., and Kaminer, B. (1994) J. Biol. Chem. 269, 23112-23119). We report on ECaSt/PDI funct...

An increase in intracellular Ca2+ concentration ([Ca2+]i) at a focal plane was recorded simultaneously with sperm-egg binding and membrane current upon insemination of sea urchin Hemicentrotus pulcherrimus eggs. No change in current and [Ca2+]i occurred in the presence of jaspisin, a novel substance that inhibits metallo-endoproteinase and sperm-egg membrane fusion (S. Ikegami, H. Kobayashi, Y....

We investigated the hypothesis that muscles of different oxidative potential would display differences in sarcoplasmic reticulum (SR) Ca2+ handling responses to repetitive contractile activity and recovery. Repetitive activity was induced in two muscles of high oxidative potential, namely, soleus (SOL) and red gastrocnemius (RG), and in white gastrocnemius (WG), a muscle of low oxidative potent...

The sarcolemmal Na(+)-Ca2+ exchanger is regulated by intracellular Ca2+ at a high affinity Ca2+ binding site separate from the Ca2+ transport site. Previous data have suggested that the Ca2+ regulatory site is located on the large intracellular loop of the Na(+)-Ca2+ exchange protein, and we have identified a high-affinity 45Ca2+ binding domain on this loop (Levitsky, D. O., D. A. Nicoll, and K...

OBJECTIVE To study a new and easy way to calculate equations to predict ionized calcium (Ca2+) for adult hospitalized patients with the usual laboratory and clinical parameters. SUBJECTS AND METHODS This retrospective observational study was conducted in a third-level university hospital. An initial learning cohort (cohort L: 269 patients) was selected to derive the new equations. These equat...

It is well established that cytochrome c is released from mitochondria when the permeability transition (PT) of this organelle is induced by Ca2+. Our previous study showed that valinomycin also caused the release of cytochrome c from mitochondria but without inducing this PT (Shinohara, Y., Almofti, M. R., Yamamoto, T., Ishida, T., Kita, F., Kanzaki, H., Ohnishi, M., Yamashita, K., Shimizu, S....