Similar effects of succinic acid dimethyl ester and glucose on islet calcium oscillations and insulin release

Mukala-Nsengu, A; Fernandez-Pascual, S; Martin, F; Martin-Del-Rio, R; Tamarit-Rodriguez, J

HERO ID

4935924

Reference Type

Journal Article

Year

2004

Language

English

PMID

15104252

HERO ID 4935924
In Press No
Year 2004
Title Similar effects of succinic acid dimethyl ester and glucose on islet calcium oscillations and insulin release
Authors Mukala-Nsengu, A; Fernandez-Pascual, S; Martin, F; Martin-Del-Rio, R; Tamarit-Rodriguez, J
Journal Biochemical Pharmacology
Volume 67
Issue 5
Page Numbers 981-988
Abstract The relative contribution of glycolysis vs. oxidative metabolism to the stimulus secretion coupling mechanism of P-cells was investigated in isolated islets. For that purpose, the secretory and intracellular calcium responses of islets to both glucose and succinic acid dimethyl ester (SAD) were compared. After 45 min of rat islet perifusion in the absence of substrates, the maximum secretory responses to Glucose (20 mmol/L) and SAD (10 mmol/L) were qualitatively and quantitatively indistinguishable. Malonic acid dimethyl ester (a permeable citric acid cycle inhibitor) suppressed the insulin secretory response to both 20 mmol/L glucose and 10 mmol/L SAD (-70% on average). The inhibitor decreased within 70% the rate of (CO2)-C-14-production from 10 mmol/L [2-C-14]pyruvate without affecting the rate of 20 mmol/L D-[5-H-3]glucose utilization. Both, 11.1 mmol/L glucose and 10 mmol/L SAD, elevated the intracellular calcium concentration and induced a similar pattern of oscillations that were rapidly ablated by 20 mmol/L malonic acid dimethyl ester. However. the intracellular concentration of calcium declined to basal values several minutes after the introduction of the inhibitor in the presence of SAD whereas it remained elevated in the case of glucose. In conclusion: (1) An exclusive increase of mitochondrial metabolism in pancreatic islets was sufficient to mimic the effects of glucose on intracellular calcium and insulin secretion. (2) Islet glycolysis and/or the re-oxidation of cytoplasmic NADH allowed the maintenance of an elevated, though non-oscillating, intracellular calcium concentration, but a reduced response to glucose. (C) 2003 Elsevier Inc. All rights reserved.
Doi 10.1016/j.bcp.2003.10.024
Pmid 15104252
Wosid WOS:000189222600020
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword insulin release; islet metabolisms; glucose; succinic and malonic acid; cytosolic calcium