PMID- 2962633
OWN - NLM
STAT- MEDLINE
DCOM- 19880318
LR  - 20190613
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 26
IP  - 22
DP  - 1987 Nov 3
TI  - IgE receptor-activated calcium permeability pathway in rat basophilic leukemia 
      cells: measurement of the unidirectional influx of calcium using quin2-buffered 
      cells.
PG  - 6995-7003
AB  - The intracellular calcium indicator and buffer quin2 has been used to generate a 
      large calcium buffering capacity in the cytoplasm of rat basophilic leukemia 
      cells. Above 3 mM intracellular quin2, there is no further increase in the 
      initial rate of antigen-induced 45Ca uptake, suggesting that 45Ca buffering by 
      quin2 is now sufficient to prevent the immediate efflux of 45Ca from the cells. 
      Thus, the initial rate of 45Ca uptake should reflect the true unidirectional 
      influx of calcium that occurs when immunoglobulin E (IgE) receptors are 
      aggregated by antigen. The antigen-induced calcium permeability pathway appears 
      to be saturable, with a Km of about 0.7 mM and a Vmax of 0.9 nmol of calcium 
      (10(6) cells)-1 min-1. Although net 45Ca uptake reaches a plateau a few minutes 
      after antigen stimulation, the increase in plasma membrane permeability is 
      maintained for at least an hour, provided that receptors for IgE remain 
      aggregated. The initial rate of 45Ca influx correlates well with the subsequent 
      secretion of [3H]serotonin in response to different concentrations of antigen. 
      Both 45Ca uptake and [3H]serotonin secretion are maximal when only 10% of the 
      receptors are occupied with antigen-specific IgE. Thus, 45Ca influx correlates 
      more closely with secretion than with the number of IgE receptors aggregated by 
      antigen.
FAU - Fewtrell, C
AU  - Fewtrell C
AD  - Department of Pharmacology, New York State College of Veterinary Medicine, 
      Cornell University, Ithaca 14853.
FAU - Sherman, E
AU  - Sherman E
LA  - eng
GR  - AI 19910/AI/NIAID NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (Aminoquinolines)
RN  - 0 (Fluorescent Dyes)
RN  - 0 (Receptors, Fc)
RN  - 0 (Receptors, IgE)
RN  - 37341-29-0 (Immunoglobulin E)
RN  - O448IDK23O (Quin2)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Aminoquinolines
MH  - Animals
MH  - Basophils/immunology/metabolism
MH  - Calcium/*metabolism
MH  - Fluorescent Dyes
MH  - Immunoglobulin E/immunology
MH  - Kinetics
MH  - Leukemia, Experimental/immunology/*metabolism
MH  - Rats
MH  - Receptors, Fc/*physiology
MH  - Receptors, IgE
EDAT- 1987/11/03 00:00
MHDA- 1987/11/03 00:01
CRDT- 1987/11/03 00:00
PHST- 1987/11/03 00:00 [pubmed]
PHST- 1987/11/03 00:01 [medline]
PHST- 1987/11/03 00:00 [entrez]
AID - 10.1021/bi00396a021 [doi]
PST - ppublish
SO  - Biochemistry. 1987 Nov 3;26(22):6995-7003. doi: 10.1021/bi00396a021.