Decreasing extracellular Na+ concentration triggers inositol polyphosphate production and Ca2+ mobilization

Journal Article · Sun Jan 15 00:00:00 EST 1989 · J. Biol. Chem.; (United States)

OSTI ID:6407835

Smith, J B; Dwyer, S D; Smith, L

Removing extracellular Na+ (Na+o) evoked a large increase in cytosolic free Ca2+ concentration ((Ca2+)i in human skin fibroblasts. Decreasing (Na+)o from 120 to 14 mM caused the half-maximal peak increase in (Ca2+)i. Removing Na+o strongly stimulated /sup 45/Ca2+ efflux and decreased total cell Ca2+ by about 40%. Bradykinin caused changes in (Ca2+)i, total Ca2+, and /sup 45/Ca2+ fluxes similar to those evoked by removing Na+o. Prior stimulation of the cells with bradykinin prevented Na+o removal from increasing (Ca2+)i and vice versa. Na+o removal rapidly increased (/sup 3/H)inositol polyphosphate production. Loading the cells with Na+ had no effect on the increase in /sup 45/Ca2+ efflux produced by Na+o removal. Therefore, decreasing (Na+)o probably stimulates a receptor(s) which is sensitive to extracellular, not intracellular, Na+. Removing Na+o also mobilized intracellular Ca2+ in smooth muscle and endothelial cells cultured from human umbilical and dog coronary arteries, respectively.

• Research Organization: Univ. of Alabama, Birmingham (USA)
• OSTI ID: 6407835
• Journal Information: J. Biol. Chem.; (United States), Vol. 264:2
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BRADYKININ
BIOCHEMICAL REACTION KINETICS
CALCIUM COMPOUNDS
MEMBRANE TRANSPORT
PHOSPHOLIPIDS
BIOSYNTHESIS
SODIUM COMPOUNDS
CALCIUM 45
CORONARIES
DOGS
ENDOTHELIUM
FIBROBLASTS
INOSITOL
MAN
MUSCLES
RECEPTORS
SKIN
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ALKALI METAL COMPOUNDS
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
ARTERIES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BLOOD VESSELS
BODY
CALCIUM ISOTOPES
CARBOHYDRATES
CARDIOVASCULAR SYSTEM
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ESTERS
EVEN-ODD NUCLEI
INOSITOLS
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
KININS
LABELLED COMPOUNDS
LIPIDS
MAMMALS
MEMBRANE PROTEINS
MONOSACCHARIDES
NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
PEPTIDES
POLYPEPTIDES
PRIMATES
PROTEINS
RADIOISOTOPES
REACTION KINETICS
SACCHARIDES
SOMATIC CELLS
SYNTHESIS
TISSUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques