Bradykinin and vasopressin stimulate Na/sup +/-K/sup +/-Cl/sup -/ cotransport in cultured endothelial cells
The authors have characterized a Na/sup +/-K/sup +/-Cl/sup -/ cotransporter in vascular endothelial cells (EC) cultured from different blood vessels and species that is inhibited by the diuretics furosemide and bumentanide. Inward /sup 86/Rb influx transported by the Na/sup +/-K/sup +/ pump in cultured EC from bovine and pig aorta, bovine vena cava, and baboon cephalic vein but not in human umbilical or saphenous vein EC. External Na/sup +/ or Cl/sup -/-stimulated, ouabain-insensitive /sup 86/Rb influx is equal to furosemide or bumetanide-sensitive /sup 86/Rb influx. Ouabain-insensitive /sup 22/Na influx is also partially inhibited by these drugs and stimulated by increasing external K/sup +/ or Cl/sup -/. Net Na/sup +/ extrusion occurs via the Na/sup +/-K/sup +/-Cl/sup -/ cotransporter in the absence of external K/sup +/, whereas net Na/sup +/ influx occurs at higher external K/sup +/. Maximal concentrations (100 nM) of bradykinin and vasopressin increase the initial rate of bumetanide-sensitive /sup 86/Rb influx by approx.60 and 70%. Addition of either ethyleneglycol-bis(..beta..-aminotethylether)-N,N'-tetraacetic acid or LaCl/sub 3/ (to block calcium influx) prevents bradykinin-stimulated /sup 86/Rb influx. When intracellular calcium is elevated using ionomycin (100 nM), a Ca/sup 2 +/ionophore, bumetanide-sensitive /sup 86/Rb influx increases approx.twofold. In contrast, isoproterenol (100 ..mu..M) and forskolin (50 /sup +/M), adenylate cyclase stimulators, decrease furosemide-sensitive /sup 86/Rb influx. Thus in certain types of cultured EC, a Na/sup +/-K/sup +/-Cl/sup -/ cotransporter mediates a fraction of K/sup +/ influx quantitatively as important as the Na/sup +/-K/sup +/ pump (ouabain-sensitive /sup 86/Rb influx) and appears to be modulated by Ca/sup 2 +/ and cyclic nucleotides.
- Research Organization:
- Harvard Medical School, Boston, MA
- OSTI ID:
- 6829546
- Journal Information:
- Am. J. Physiol.; (United States), Vol. 250:6
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BRADYKININ
BIOLOGICAL EFFECTS
ENDOTHELIUM
PHYSIOLOGY
RUBIDIUM 86
MEMBRANE TRANSPORT
VASOPRESSIN
AMP
BLOOD VESSELS
CELL CULTURES
CHLORIDES
IONS
POTASSIUM COMPOUNDS
SODIUM COMPOUNDS
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ANIMAL TISSUES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR SYSTEM
CHARGED PARTICLES
CHLORINE COMPOUNDS
DAYS LIVING RADIOISOTOPES
HALIDES
HALOGEN COMPOUNDS
HORMONES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KININS
MINUTES LIVING RADIOISOTOPES
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PEPTIDES
PITUITARY HORMONES
POLYPEPTIDES
PROTEINS
RADIOISOTOPES
RUBIDIUM ISOTOPES
TISSUES
551001* - Physiological Systems- Tracer Techniques