IgE receptor-activated calcium permeability pathway in rat basophilic leukemia cells

Conference · Sat Mar 01 04:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5498330

Fewtrell, C; Sherman, E; Mohr, F C

When antigen-stimulated /sup 45/Ca uptake is measured in RBL cells loaded with > 3 mM quin2, re-extrusion of /sup 45/Ca is minimized and the initial rate of /sup 45/Ca uptake reflects the true unidirectional influx of Ca. This influx correlates more closely with secretion than with the number of IgE receptors aggregated by antigen. The antigen-induced permeability pathway is saturable, having a Km of about 0.7 mM and a Vmax of 0.9 nmol Ca/10/sup 6/ cells/min and it persists for at least an hour provided that receptor aggregation is maintained. The negatively charged fluorescent probe bis-oxonol is insensitive to changes in the mitochondrial membrane potential and is, therefore, a useful plasma membrane potential indicator. Antigen-stimulation of RBL cells equilibrated with bis-oxonol causes a rapid depolarization that peaks within 2-3 minutes and persists until receptor aggregates are disrupted. Antigen-induced depolarization is seen in the absence of extracellular calcium, but is almost completely abolished when both sodium and calcium are replaced by glucose. Addition of calcium restores this response even when sodium is absent. This suggests that the IgE receptor-activated permeability pathway has a similar conductance for sodium and calcium ions.

• Research Organization: Cornell Univ., Ithaca, NY
• OSTI ID: 5498330
• Report Number(s): CONF-8604222-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:3
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METALS
ANIMALS
ANTIGENS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL PATHWAYS
CALCIUM
CALCIUM 45
CALCIUM ISOTOPES
CELL CONSTITUENTS
CELL MEMBRANES
DAYS LIVING RADIOISOTOPES
DISEASES
ELEMENTS
EVEN-ODD NUCLEI
GLOBULINS
HEMIC DISEASES
IMMUNOGLOBULINS
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LEUKEMIA
MAMMALS
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
MEMBRANES
METALS
MITOCHONDRIA
NEOPLASMS
NUCLEI
ORGANIC COMPOUNDS
ORGANOIDS
PERMEABILITY
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
TRACER TECHNIQUES
VERTEBRATES