Identical regional mechanisms of intracellular free Ca2+ concentration increase during polarized agonist-evoked Ca2+ response in pancreatic acinar cells.
The initial increase of intracellular free Ca2+ concentration ([Ca2+]i) following agonist stimulation is spatially restricted to one pole of the cell, from where a wave of [Ca2+]i spreads across the cytosol. In the present study we have investigated the dynamic properties of the agonist-activated Ca(2+)-release mechanisms in different regions of the acinar cell and show that, during maximal agonist stimulation, the rate of [Ca2+]i increase at the secretory pole is identical with that recorded at the basal pole. Furthermore, the relationship between [Ca2+]i and the apparent rate of [Ca2+]i increase is similar in both regions of the cell. The data show that whereas the sensitivity to the Ca(2+)-releasing agent is different in different regions of the cell, the process of [Ca2+]i increase, once triggered, will proceed in an identical fashion, irrespective of the area of the cell.
Toescu
E C
EC
Department of Physiology, University of Birmingham, School of Medicine, Edgbaston, U.K.
Gallacher
D V
DV
Petersen
O H
OH
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D016257:Fura-2; D051379:Mice; D008954:Models, Biological; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*
D000109:Acetylcholine; D002118:Calcium; D016257:Fura-2