Please use this identifier to cite or link to this item: http://ahro.austin.org.au/austinjspui/handle/1/12474
Title: Extracellular adenosine triphosphate increases cation permeability of chronic lymphocytic leukemic lymphocytes.
Authors: Wiley, J S;Dubyak, G R
Affiliation: Hematology Department, Austin Hospital, Melbourne, Australia.
Issue Date: 1-Apr-1989
Citation: Blood; 73(5): 1316-23
Abstract: 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 (complete within 30 seconds) 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. These actions of ATP were specific in that equimolar concentrations of other nucleotides were without effect. These data indicate that treatment of CLL lymphocytes with extracellular ATP4 produces large increases in cation permeability. In contrast, there is less or no ATP-induced permeabilization of normal PBL.
Internal ID Number: 2539215
URI: http://ahro.austin.org.au/austinjspui/handle/1/12474
URL: http://www.ncbi.nlm.nih.gov/pubmed/2539215
Type: Journal Article
Subjects: Adenosine Triphosphate.physiology
Calcium.blood
Cell Membrane Permeability
Cells, Cultured
Cytosol.metabolism
Extracellular Space.metabolism.pathology.physiology
Humans
Leukemia, Lymphocytic, Chronic, B-Cell.blood.pathology
Lithium.metabolism
Lymphocytes.metabolism.pathology
Rubidium Radioisotopes
Sodium Channels.metabolism
Sodium Radioisotopes
Appears in Collections:Journal articles

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