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INTERACTIONS OF Na + , H 2 O 2 AND THE Na + ‐Ca 2+ EXCHANGER STIMULATE Ca 2+ RELEASE IN CK1.4 CELLS
Author(s) -
Fang Yan,
Rong Mingyang,
He Lianfang
Publication year - 1997
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.1997.tb01803.x
Subject(s) - chemistry , chinese hamster ovary cell , ion exchange , nuclear chemistry , calcium , extracellular , analytical chemistry (journal) , ion , biochemistry , chromatography , receptor , organic chemistry
SUMMARY 1. The present study aimed to demonstrate that interactions of cations, hydrogen peroxide (H 2 O 2 ) and the Na + ‐Ca 2+ exchanger stimulate Ca 2+ release and oscillations of cytosolic Ca 2+ [Ca 2+ ]i in non‐transfected Chinese Hamster Ovary (CHO) C1 cells and in transfected CHO (CK1.4) cells that contained an expression vector coding the Na + ‐Ca 2+ exchanger sequence. 2. The [ 45 Ca 2+ ] uptake assay, fura‐2 fluorescence imaging and 2 2 and 2 3 factorial orthogonal statistics provide comparative, direct, efficient, quantitative and transient methods to delineate the effects of such interactions on Ca 2+ influx, Ca 2+ release and [Ca 2+ ]i in C1 and CK1.4 cells. 3. In contrast to the control of either Na + ‐, Ca 2+ ‐ or H 2 O 2 ‐free or CI cells, an elevated [ 45 Ca 2+ ] uptake was induced by Ca 2+ , Na + and H 2 O 2 individually and in combination, intracellular Ca 2+ release was activated by H 2 O 2 and by combinations of either H 2 O 2 and Na + , H 2 O 2 and the Na + ‐Ca 2+ exchanger, Na + and the Na + ‐Ca 2+ exchanger or by H 2 O 2 , Na + and the Na + ‐Ca 2+ exchanger and a rise in [Ca 2+ ]i was triggered by H 2 O 2 , Na + and a combination of Na + and the Na + ‐Ca 2+ exchanger. 4. These results indicate that interactions between H 2 O 2 , Na + and the Na + ‐Ca 2+ exchanger stimulate intracellular Ca 2+ mobilization via Ca 2+ ‐induced Ca 2+ release mechanisms, ATP‐activated G‐protein coupled P 2y ‐purinoceptor‐sensitive pathways, Na + ‐Ca 2+ exchanger‐mediated Ca 2+ influx and cation‐π interaction (a strong non‐covalent force between the cation and the π face of an aromatic structure in the transmembrane protein). 5. The present findings provide important clues for understanding Ca 2+ signal transduction mechanisms from the plasma membrane to the endoplasmic reticulum.