Please use this identifier to cite or link to this item:
https://hdl.handle.net/10316/3894
Title: | Glucose-mediated Ca2+ signalling in single clonal insulin-secreting cells: evidence for a mixed model of cellular activation | Authors: | Salgado, António P. Santos, Rosa M. Fernandes, Ana P. Tomé, Ângelo R. Flatt, Peter R. Rosário, Luís M. |
Keywords: | Pancreatic [beta]-cell line; Glucose metabolism; Ca2+ oscillations; Fura-2 fluorescence; Cellular heterogeneity | Issue Date: | 2000 | Citation: | The International Journal of Biochemistry & Cell Biology. 32:5 (2000) 557-569 | Abstract: | Using clonal insulin-secreting BRIN-BD11 cells, we have assessed whether the graded response of the whole cell population to glucose can be accounted for by a dose-dependent recruitment of individual cells, an amplification of the response of the recruited cells or both. Cytosolic free Ca2+ concentration ([Ca2+]i) is an established index of [beta]-cell function. We used fura-2 microfluorescence techniques to assess the [Ca2+]i responsiveness of single BRIN-BD11 cells to glucose and other secretagogues. Glucose (1-16.7Â mM) evoked oscillatory [Ca2+]i rises in these cells resembling those found in parental rat pancreatic [beta]-cells. The percentage of glucose-responsive cells was 11% at 1Â mM and increased to 40-70% at 3-16.7Â mM glucose, as assessed by a single-stimulation protocol. This profile was unrelated to possible differences in the cell cycle, as inferred from experiments where the cultured cells were synchronized by a double thymidine block protocol. Individual cells exhibited variable sensitivities to glucose (threshold range: 1-5Â mM) and a variable dose-dependent amplification of the [Ca2+]i responses (EC50 range: 2-10Â mM), as assessed by a multiple-stimulation protocol. Glyceraldehyde and [alpha]-ketoisocaproic acid had glucose-like effects on [Ca2+]i. The data support a mixed model for the activation of insulin-secreting cells. Specifically, the graded secretory response of the whole cell population is likely to reflect both a recruitment of individual cells with different sensitivities to glucose and a dose-dependent amplification of the response of the recruited cells. | URI: | https://hdl.handle.net/10316/3894 | DOI: | 10.1016/S1357-2725(99)00146-6 | Rights: | openAccess |
Appears in Collections: | FCTUC Ciências da Vida - Artigos em Revistas Internacionais |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
filefcdac3dafe3e43c0827329b507ebca0a.pdf | 505.98 kB | Adobe PDF | View/Open |
SCOPUSTM
Citations
13
checked on Nov 11, 2022
WEB OF SCIENCETM
Citations
11
checked on May 2, 2023
Page view(s)
327
checked on Oct 16, 2024
Download(s)
278
checked on Oct 16, 2024
Google ScholarTM
Check
Altmetric
Altmetric
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.