Extracellular adenosine triphosphate increases cation permeability of chronic lymphocytic leukemic lymphocytes
Extracellular adenosine triphosphate (ATP) is known to reversibly increase the cation permeability of a variety of freshly isolated and cultured cell types. In this study the effects of extracellular ATP were studied using peripheral blood lymphocytes (PBL) isolated from both normal subjects and from patients with chronic lymphocytic leukemia (CLL). Changes in the permeability to Na+, Rb+, and Li+ ions were measured using conventional isotope and flame photometry techniques. In addition, changes in cytosolic (Ca2+) were fluorimetrically monitored to assess possible changes in net Ca2+ influx. ATP produced a 12-fold increase in 22Na+ influx into CLL cells but only a 3.5-fold increase in this flux in PBL cells. A maximal response was produced by 0.1 mmol/L ATP in the absence of Mg2+, while a twofold molar excess of Mg2+ over ATP abolished the response. ATP had no effect on the passive (ouabain-insensitive) 86Rb+ influx into PBL cells but stimulated this flux by fivefold in the CLL cells. Li+ influx into CLL cells was also stimulated threefold by ATP. Under these same conditions ATP also produced a net increase in total cell Na and a decrease in total cell K in the CLL cells. Exclusion of two normally impermeable dyes, trypan blue and ethidium bromide, was not altered in the ATP-treated CLL cells. Finally, extracellular ATP (3 mmol/L) produced no significant change in the cytosolic (Ca2+) of normal, monocyte-depleted populations of PBL. Conversely, this same concentration of ATP produced a very rapid and a significant (an average threefold peak change) increase in the cytosolic (Ca2+) of cell preparations derived from five out of nine CLL patients. In these latter CLL cells, the ATP-induced elevation in cytosolic (Ca2+) appeared to be due to a net increase in Ca2+ influx, since no elevations were observed when the extracellular (Ca2+) was reduced to less than 0.1 mmol/L.
- Research Organization:
- Austin Hospital, Melbourne (Australia)
- OSTI ID:
- 6075950
- Journal Information:
- Blood; (United States), Vol. 73:5
- Country of Publication:
- United States
- Language:
- English
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ATP
BIOCHEMICAL REACTION KINETICS
CALCIUM COMPOUNDS
MEMBRANE TRANSPORT
CELL MEMBRANES
PERMEABILITY
LITHIUM COMPOUNDS
RUBIDIUM COMPOUNDS
SODIUM COMPOUNDS
CATIONS
CELL CULTURES
EXTRACELLULAR SPACE
LEUKEMIA
LYMPHOCYTES
MAN
SODIUM 22
TRACER TECHNIQUES
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CELL CONSTITUENTS
CHARGED PARTICLES
CONNECTIVE TISSUE CELLS
DISEASES
HEMIC DISEASES
IMMUNE SYSTEM DISEASES
IONS
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LEUKOCYTES
LIGHT NUCLEI
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MEMBRANES
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REACTION KINETICS
SODIUM ISOTOPES
SOMATIC CELLS
SPACE
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YEARS LIVING RADIOISOTOPES
550201* - Biochemistry- Tracer Techniques
550901 - Pathology- Tracer Techniques