A new technique for assessing the microscopic distribution of cellular calcium exit sites.
This paper contains a description of a new method designed to monitor the distribution of Ca2+ efflux from cells or small cellular aggregates. The idea behind this method is to use a fluorescent Ca2+ indicator bound to dextrans of high molecular weight to slow down Ca2+ diffusion. Due to the decrease in diffusion rate, Ca2+ ions should be held close to the site of their release from the cells for a relatively long time, enough for the confocal microscope to detect such a local increase in Ca2+ concentration. This paper gives a detailed description of the method, illustrated with results of measurements of agonist-dependent and agonist-independent Ca2+ extrusion from pancreatic acinar cells. An appendix provides the mathematical background that should allow selection of the concentration of buffer which is necessary to achieve a particular Ca2+ diffusion coefficient.
Belan
P V
PV
MRC Secretory Control Research Group, The Physiological Laboratory, University of Liverpool, PO Box 147, Crown Street, Liverpool L69 3BX, UK.
Gerasimenko
O V
OV
Berry
D
D
Saftenku
E
E
Petersen
O H
OH
Tepikin
A V
AV
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003911:Dextrans; D005456:Fluorescent Dyes; D051379:Mice; D018613:Microscopy, Confocal; D009930:Organic Chemicals; D009994:Osmolar Concentration; D010179:Pancreas / Q000166:cytology / Q000378:metabolism*; D010827:Physiology / Q000379:methods*; D014018:Tissue Distribution
D003911:Dextrans; D005456:Fluorescent Dyes; D009930:Organic Chemicals; C071336:calcium green; D000109:Acetylcholine; D002118:Calcium