Redistribution of Ca 2+ among cytosol and organella during stimulation of bovine chromaffin cells

2002 ◽  
Vol 16 (3) ◽  
pp. 343-353 ◽  
Author(s):  
Carlos Villalobos ◽  
Lucía Nuñez ◽  
Mayte Montero ◽  
Antonio G. García ◽  
Maria Teresa Alonso ◽  
...  
Keyword(s):  
Chromaffin Cells ◽  
Bovine Chromaffin Cells ◽  
Stimulation Of

scholarly journals Anti-(14–3–3 protein) antibody inhibits stimulation of noradrenaline (norepinephrine) secretion by chromaffin-cell cytosolic proteins

1992 ◽  
Vol 285 (3) ◽  
pp. 697-700 ◽  
Author(s):  
Y N Wu ◽  
N D Vu ◽  
P D Wagner
Keyword(s):  
Sequence Analysis ◽  
Chromaffin Cells ◽  
Chromaffin Cell ◽  
Significant Contribution ◽  
Secretory Activity ◽  
Bovine Brain ◽  
Cytosolic Proteins ◽  
Sequence Identity ◽  
Bovine Chromaffin Cells ◽  
Stimulation Of

Incubation of digitonin-permeabilized bovine chromaffin cells in the absence of Ca2+ results in a loss of both cytosolic proteins and Ca(2+)-dependent secretion. Addition of these leaked proteins prevents this loss of secretory activity. We have purified a protein from an extract of bovine adrenal medulla which can partially prevent this loss of Ca(2+)-dependent secretion. Antibody against this protein inhibited the ability of leaked chromaffin-cell proteins to prevent the loss of Ca(2+)-dependent secretion. Sequence analysis showed it to have sequence identity with bovine brain 14-3-3 protein. These results demonstrate that 14-3-3 protein makes a significant contribution to the ability of leaked chromaffin-cell proteins to maintain secretory activity.

Permeation and inactivation by calcium and manganese of bovine adrenal chromaffin cell calcium channels

1992 ◽  
Vol 263 (4) ◽  
pp. C818-C824 ◽  
Author(s):  
R. I. Fonteriz ◽  
J. Garcia-Sancho ◽  
L. Gandia ◽  
M. G. Lopez ◽  
A. G. Garcia
Keyword(s):  
Chromaffin Cells ◽  
Chromaffin Cell ◽  
Divalent Cations ◽  
Receptor Activation ◽  
Adrenal Chromaffin Cell ◽  
High K ◽  
Bovine Chromaffin Cells ◽  
Adrenal Chromaffin ◽  
Ca2 Channels ◽  
Stimulation Of

Stimulation of fura-2-loaded bovine chromaffin cells with the nicotinic agonist 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP; 10 microM) or depolarization with high [K+] (50 mM) accelerated the entry of both Ca2+ and Mn2+, used here as a Ca2+ surrogate for Ca2+ channels. Removal of extracellular Na+ prevented the effects of DMPP but did not modify the effects of K+, indicating that Na+ is necessary for coupling of Ca2+ entry to the nicotinic receptor activation and that the ionophore associated with it is functionally impermeable to divalent cations. DMPP- as well as K(+)-evoked Ca2+ and Mn2+ influx were blocked completely by Ni2+ but only partially by dihydropyridines, suggesting that, in addition to L-type Ca2+ channels, other Ca2+ entry pathways may be present. Inactivation of Ca2+ channels, followed by comparing the rates of Mn2+ uptake at different time periods after the addition of DMPP or high K+, did not happen in the absence of extracellular Ca2+. When 1 mM Ca2+ was present, a delayed inhibition (half time, 10-20 s) was observed, suggesting that it is not due to the entry of Ca2+ itself but to the increase of the cytoplasmic Ca2+ concentration ([Ca2+]i) that takes a few seconds to develop. The influx of Ca2+, estimated from the increase of [Ca2+]i, was also impaired in a time-dependent fashion by previous entry of Mn2+. Inactivation of Ca2+ entry was achieved at estimated mean intracellular Mn2+ concentrations as low as 10(-9) M.

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