Role for Na/sup +/, H/sup +/, and Ca/sup 2 +/ during (/sup 3/H)-serotonin release from rat basophilic leukemia cells

Conference · Wed Mar 05 04:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6828237

Stump, R F; Oliver, J M; Deanin, G G

The authors have investigated the roles of Na/sup +/, pH, and Ca/sup 2 +/ in the release of (/sup 3/H)-serotonin from RBL-2H3 cells. The importance of extracellular Ca/sup 2 +/ for antigen-induced mediator release is well known. The authors report that mediator release also depends on extracellular Na/sup +/ and that the Na/sup +/ ionophore, monensin, like the Ca/sup 2 +/ ionophores A23187 and ionomycin, mimics antigen in causing release. Amiloride suppresses serotonin release, indicating that antigen activates the Na/sup +//H/sup +/ antiport. Antigen-stimulated Na/sup +//H/sup +/ exchange (and/or the resulting cytoplasmic alkalinization) may affect mediator release in part by controlling cytoplasmic free Ca/sup 2 +/ levels. The authors report that antigen normally causes a spike followed by a plateau of Ca/sup 2 +/-Quin 2 fluorescence. Only the spike occurs when cells are incubated with antigen in low Na/sup +/ medium. Conversely, monensin produces a Ca/sup 2 +/ plateau without a spike phase. In addition, cytoplasmic alkalinization due to increased Na/sup +//H/sup +/ exchange may directly cause secretion. Both NH/sub 4/Cl and monensin cause mediator release in Ca/sup 2 +/-free medium: these reagents increase pH by about 0.1 units as measured by the fluorescent dye, BCECF. TPA that stimulates Na/sup +//H/sup +/ exchange in other cells does not cause release directly but it potentiates both antigen and Ca/sup 2 +/ ionophore-induced release in RBL-2h3 cells. This further suggests synergistic roles for Na/sup +//H/sup +/ exchange and Ca/sup 2 +/ mobilization in the control of mediator release.

• Research Organization: Univ. of New Mexico Medical School, Albuquerque
• OSTI ID: 6828237
• Report Number(s): CONF-8604222-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:4
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
AMINES
ANIMAL CELLS
ANIMALS
ANTIGENS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
AZOLES
BIOLOGICAL EFFECTS
CALCIUM COMPOUNDS
CARCINOGENS
DISEASES
DRUGS
ESTERS
HEMIC DISEASES
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INDOLES
ION EXCHANGE
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEUKEMIA
MAMMALS
MEMBRANE TRANSPORT
NEOPLASMS
NEUROREGULATORS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHORBOL ESTERS
PYRROLES
RADIOPROTECTIVE SUBSTANCES
RATS
RODENTS
SECRETION
SEROTONIN
SODIUM COMPOUNDS
SYMPATHOMIMETICS
SYNERGISM
TRACER TECHNIQUES
TRITIUM COMPOUNDS
TRYPTAMINES
TUMOR CELLS
VERTEBRATES