EGF raises cytosolic Ca sup 2+ in A431 and Swiss 3T3 cells by a dual mechanism
- Univ. of Milano (Italy)
The changes in Ca{sup 2+} homeostasis and phosphoinositide hydrolysis induced by EGF were studied in human epidermoid carcinoma A431 cells both when attached to a substratum and after detachment and suspension. The cytosolic Ca{sup 2+} concentration was measured by the conventional fluorimetric technique, using the specific probe, quin2, as well as by a new microscopic technique in which single cells are investigated after loading with another probe, fura-2. EGF applied in the complete, Ca{sup 2+}-containing medium caused a rapid rise in the cytosolic {sup 45}Ca{sup 2+} concentration, that remained elevated for several minutes. In Ca{sup 2+}-free, EGTA-containing medium, part of this response persisted, as revealed by quin2 results in suspended cells and microscopic results with fura-2. These results, as well as additional microscopic fura-2 results in Swiss 3T3 fibroblasts, demonstrate that the Ca{sup 2+} signal elicited by EGF is due to two components: redistribution from an intracellular store and stimulated influx across the plasmalemma. This latter process was not detected in 3T3 cells treated with either PDGF or bombesin. It is therefore suggested that the {sup 45}Ca{sup 2+} influx effect of EGF is under the control of a separate, as yet unidentified mechanism.
- OSTI ID:
- 6531079
- Journal Information:
- Experimental Cell Research; (USA), Vol. 170:1; ISSN 0014-4827
- Country of Publication:
- United States
- Language:
- English
Similar Records
Early events elicited by bombesin and structurally related peptides in quiescent Swiss 3T3 cells. II. Changes in Na/sup +/ and Ca/sup 2 +/ fluxes, Na/sup +//K/sup +/ pump activity, and intracellular pH
Early events elicited by Bombesin and structurally related peptides in quiescent Swiss 3T3 cells. I. Activation of protein kinase C and inhibition of epidermal growth factor binding
Related Subjects
CALCIUM 45
MEMBRANE TRANSPORT
GROWTH FACTORS
BIOLOGICAL EFFECTS
BIOLOGICAL PATHWAYS
CALCIUM COMPOUNDS
CARCINOMAS
CELL MEMBRANES
FIBROBLASTS
FLUORESCENCE SPECTROSCOPY
HOMEOSTASIS
INOSITOLS
MAN
TUMOR CELLS
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CALCIUM ISOTOPES
CARBOHYDRATES
CELL CONSTITUENTS
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
DISEASES
EMISSION SPECTROSCOPY
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
ISOTOPES
MAMMALS
MEMBRANES
MITOGENS
MONOSACCHARIDES
NEOPLASMS
NUCLEI
ORGANIC COMPOUNDS
PRIMATES
PROTEINS
RADIOISOTOPES
SACCHARIDES
SOMATIC CELLS
SPECTROSCOPY
VERTEBRATES
550301* - Cytology- Tracer Techniques