Isolated mouse pancreatic beta-cells show cell-specific temporal response pattern.
The length of the silent lag time before elevation of the cytosolic free Ca2+ concentration ([Ca2+]i) differs between individual pancreatic beta-cells. One important question is whether these differences reflect a random phenomenon or whether the length of lag time is inherent in the individual beta-cell. We compared the lag times, initial dips, and initial peak heights for [Ca2+]i from two consecutive glucose stimulations (with either 10 or 20 mM glucose) in individual ob/ob mouse beta-cells with the fura 2 technique in a microfluorimetric system. There was a strong correlation between the lengths of the lag times in each beta-cell (10 mM glucose: r = 0.94, P < 0.001; 20 mM glucose: r = 0.96, P < 0.001) as well as between the initial dips in [Ca2+]i (10 mM glucose: r = 0.93, P < 0.001; 20 mM glucose: r = 0.79, P < 0.001) and between the initial peak heights (10 mM glucose: r = 0.51, P < 0.01; 20 mM glucose: r = 0.77, P < 0.001). These data provide evidence that the response pattern, including both the length of the lag time and the dynamics of the subsequent [Ca2+]i, is specific for the individual beta-cell.
Larsson-Nyrén
Gerd
G
Department of Integrative Medical Biology, Section for Histology and Cell Biology, Umeå University, SE-901 87 Umeå, Sweden. gerd.larsson-nyren@histocel.umu.se
Pakhtusova
Natalia
N
Sehlin
Janove
J
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002469:Cell Separation; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D005456:Fluorescent Dyes; D016257:Fura-2; D005947:Glucose / Q000494:pharmacology; D007424:Intracellular Fluid / Q000378:metabolism; D007515:Islets of Langerhans / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008820:Mice, Obese; D011930:Reaction Time / Q000502:physiology; D013268:Stimulation, Chemical
D005456:Fluorescent Dyes; D005947:Glucose; D002118:Calcium; D016257:Fura-2