Glucose stimulation of transmembrane chloride flux in individual pancreatic β-cells demonstrated with a microfluorometric technique

2000 ◽  
Vol 50 ◽  
pp. 148
Author(s):  
E Grapengiesser ◽  
M Eberhardson ◽  
S Patterson
Keyword(s):  
Β Cells ◽  
Pancreatic Β Cells ◽  
Glucose Stimulation ◽  
Chloride Flux ◽  
Stimulation Of

Ca2+Transport in Pancreatic β-Cells during Glucose Stimulation of Insulin Secretion

1980 ◽  
Vol 85 (3) ◽  
pp. 321-329 ◽  
Author(s):  
Bo Hellman ◽  
Erik Gylfe ◽  
Per-Olof Berggren ◽  
Tommy Andersson ◽  
Håkan Abrahamsson ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Glucose Stimulation ◽  
Stimulation Of

scholarly journals Mitochondrial–Endoplasmic Reticulum Interplay: A Lifelong On–Off Relationship?

Contact ◽  
2019 ◽  
Vol 2 ◽  
pp. 251525641986122 ◽  
Author(s):  
Corina T. Madreiter-Sokolowski ◽  
Roland M. Malli ◽  
Wolfgang F. Graier
Keyword(s):  
Endoplasmic Reticulum ◽  
Adenosine Triphosphate ◽  
Therapeutic Strategies ◽  
Mitochondrial Activity ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Potential Target ◽  
Pathological Conditions ◽  
Elevated Glucose ◽  
Stimulation Of

This article comments recent publications that highlight an intriguing importance of specific settings in the interaction between the mitochondria and the endoplasmic reticulum to ensure cell-specific functions like the responsiveness to elevated glucose in pancreatic β-cells. Hence, alterations of the mitochondria–endoplasmic reticulum communications under various pathological conditions like aging or cancer often come with enhanced Ca2+ transfer that, in turn, yields stimulation of basal mitochondrial activity to meet the increasing adenosine triphosphate demand of the very cell. Such observations identify mitochondria-associated membranes as potential target for new therapeutic strategies against aging or cancer.

Studies of the mechanism of amino acid-induced stimulation of insulin secretion from clonal pancreatic β-cells

2000 ◽  
Vol 28 (5) ◽  
pp. A196-A196
Author(s):  
A. Shine ◽  
N. H. Mc Clenaghan ◽  
P. Flatt ◽  
JPG Malthouse ◽  
C. Hewage ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Amino Acid ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Stimulation Of

Carbamoylcholine regulation of polyphosphoinositide synthesis and hydrolysis in cultured, dispersed, digitonin-permeabilized mouse pancreatic islet cells

1997 ◽  
Vol 136 (5) ◽  
pp. 539-545 ◽  
Author(s):  
Andrew M Kardasz ◽  
Peter Thams ◽  
Kirsten Capito ◽  
Carl J Hedeskov
Keyword(s):  
Pancreatic Islet ◽  
Kinase Activity ◽  
Inositol Phosphates ◽  
Islet Cells ◽  
Pancreatic Islet Cells ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Mouse Pancreatic Islet ◽  
Phosphatidylinositol 4 ◽  
Stimulation Of

Abstract Continuing formation of inositol phosphates during stimulation of pancreatic β-cells by hormones and neurotransmitters requires the continued synthesis of the polyphosphoinositides phosphatidylinositol 4-phosphate (PIP) and phosphatidylinositol 4,5 bisphosphate (PIP2) from phosphatidylinositol (PI). In the present study we have investigated how this pathway and the activity of phosphoinositide-specific phospholipase C (PI-PLC) are regulated by carbamoylcholine (CCh), Ca2+, the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA), GTPγS and NaF in 44-h [3H]inositol-labelled, dispersed and digitonin-permeabilized mouse pancreatic islet cells. CCh stimulated not only PI-PLC (G-protein-mediated) but also, by an as yet unknown mechanism, significantly enhanced PI 4-kinase activity, estimated as the PIP:PI ratio, by 100%, and further increased the flux from PI to PIP and PIP2. GTPγS and NaF mimicked the effects of CCh on PI-PLC but had no effect on the levels of PIP and PIP2. TPA raised the PIP:PI ratio by 75%. In addition TPA counteracted the CCh stimulation of PI-PLC. There was no effect of 10−6 mol/l Ca2+ on the levels of PIP and PIP2. Experiments with quinacrine and adenosine confirmed that PI-PLC and PI 4-kinase could be regulated independently of each other. In conclusion, these data point to differential regulation of polyphosphoinositide synthesis and breakdown. European Journal of Endocrinology 136 539–545

scholarly journals Direct Stimulation of Basal Insulin Secretion by Physiological Concentrations of Leptin in Pancreatic β Cells

Endocrinology ◽  
1997 ◽  
Vol 138 (10) ◽  
pp. 4513-4516 ◽  
Author(s):  
Yukio Tanizawa ◽  
Shigeru Okuya ◽  
Hisamitsu Ishihara ◽  
Tomoichiro Asano ◽  
Toshihiko Yada ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Basal Insulin ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Direct Stimulation ◽  
Basal Insulin Secretion ◽  
Stimulation Of

Calcium and pancreatic β-cell function. 12. Modification of 45Ca fluxes by excess of K+

1981 ◽  
Vol 96 (1) ◽  
pp. 87-92 ◽  
Author(s):  
T. Andersson ◽  
C. Betsholtz ◽  
B. Hellman
Keyword(s):  
Cell Function ◽  
Secretory Granules ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Deficient Medium ◽  
Β Cell Function ◽  
Cell Handling ◽  
Stimulation Of ◽  
Glucose Effects

Abstract. Glucose stimulation of insulin release is supposed to result from depolarization of the pancreatic β-cells with subsequent influx of Ca2+. Isolated islets from non-inbred ob/ob-mice were employed for elucidating whether the glucose effects on the β-cell handling of Ca2+ could be simulated by the depolarization evoked by excess of K+. Addition of 25 mm K+ was as effective as 20 mm glucose in stimulating the intracellular uptake of 45Ca. In both instances the additional amounts of incorporated 45Ca appeared in the mitochondria and the secretory granules. When analysing the washout pattern for 45Ca it was evident that the effects of raising K+ differed from those evoked by glucose. Whereas glucose inhibited 45Ca efflux during perifusion with Ca2+-deficient medium the addition of K+ resulted in a slight stimulation. Furthermore, the 45Ca incorporated in response to K+ was more readily mobilised.

Contribution of the endoplasmic reticulum to the glucose-induced [Ca2+]c response in mouse pancreatic islets

2002 ◽  
Vol 282 (5) ◽  
pp. E982-E991 ◽  
Author(s):  
Abdelilah Arredouani ◽  
Jean-Claude Henquin ◽  
Patrick Gilon
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Membrane Potential ◽  
Glucose Concentration ◽  
Buffering Capacity ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Glucose Stimulation ◽  
Mouse Pancreatic Islets ◽  
Fast Oscillations

Thapsigargin (TG), a blocker of Ca2+ uptake by the endoplasmic reticulum (ER), was used to evaluate the contribution of the organelle to the oscillations of cytosolic Ca2+ concentration ([Ca2+]c) induced by repetitive Ca2+ influx in mouse pancreatic β-cells. Because TG depolarized the plasma membrane in the presence of glucose alone, extracellular K+ was alternated between 10 and 30 mM in the presence of diazoxide to impose membrane potential (MP) oscillations. In control islets, pulses of K+, mimicking regular MP oscillations elicited by 10 mM glucose, induced [Ca2+]c oscillations whose nadir remained higher than basal [Ca2+]c. Increasing the depolarization phase of the pulses while keeping their frequency constant (to mimic the effects of a further rise of the glucose concentration on MP) caused an upward shift of the nadir of [Ca2+]c oscillations that was reproduced by raising extracellular Ca2+ (to increase Ca2+influx) without changing the pulse protocol. In TG-pretreated islets, the imposed [Ca2+]c oscillations were of much larger amplitude than in control islets and occurred on basal levels. During intermittent trains of depolarizations, control islets displayed mixed [Ca2+]c oscillations characterized by a summation of fast oscillations on top of slow ones, whereas no progressive summation of the fast oscillations was observed in TG-pretreated islets. In conclusion, the buffering capacity of the ER in pancreatic β-cells limits the amplitude of [Ca2+]c oscillations and may explain how the nadir between oscillations remains above baseline during regular oscillations or gradually increases during mixed [Ca2+]c oscillations, two types of response observed during glucose stimulation.

[Ca2+]i regulates trafficking of Cav1.3 (α1D Ca2+ channel) in insulin-secreting cells

2004 ◽  
Vol 286 (2) ◽  
pp. C213-C221 ◽  
Author(s):  
Luping Huang ◽  
Arin Bhattacharjee ◽  
James T. Taylor ◽  
Min Zhang ◽  
Brian M. Keyser ◽  
...  
Keyword(s):  
Surface Proteins ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Glucose Stimulation ◽  
Channel Trafficking ◽  
Insulin Secreting Cells ◽  
High Concentrations ◽  
The Relationship ◽  
Insulin Secretory Response

Chronic exposure of pancreatic β-cells to high concentrations of glucose impairs the insulin secretory response to further glucose stimulation. This phenomenon is referred to as glucose desensitization. It has been shown that glucose desensitization is associated with abnormal elevation of β-cell basal intracellular free Ca2+ concentration ([Ca2+]i). We have investigated the relationship between the basal intracellular free Ca2+ and the L-type (Cav1.3) Ca2+ channel translocation in insulin-secreting cells. Glucose stimulation or membrane depolarization induced a nifedipine-sensitive Ca2+ influx, which was attenuated when the basal [Ca2+]i was elevated. Using voltage-clamp techniques, we found that changing [Ca2+]i could regulate the amplitude of the Ca2+ current. This effect was attenuated by drugs that interfere with the cytoskeleton. Immunofluorescent labeling of Cav1.3 showed an increase in the cytoplasmic distribution of the channels under high [Ca2+]i conditions by deconvolution microscopy. The [Ca2+]i-dependent translocation of Cav1.3 channel was also demonstrated by Western blot analysis of biotinylation/NeutrAvidin-bead-eluted surface proteins in cells preincubated at various [Ca2+]i. These results suggest that Cav1.3 channel trafficking is involved in glucose desensitization of pancreatic β-cells.

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