Abstract
A bioluminescent method is presented that allows monitoring of ATP production from mitochondria corresponding to one islet of Langerhans per sample. In mitochondria from ob/ob mice Ca2+ stimulates the ATP production in the presence of L-glycerol 3-phosphate (GP) by reducing the Km for GP by one order of magnitude to about 3 mM. Maximal ATP production in the presence of Ca2+ (200 nM) is obtained at 10 mM GP. The free calcium concentration required to reach half-maximal stimulation (K0.5Ca2+) depends on the GP concentration, thus half-maximal effects are observed at about 80 nM at low GP (1 mM) and 10 nM at high GP (10 mM). Sodium can replace Ca2+ as a stimulator of GP-induced ATP production. It activates ADP phosphorylation by B-cell mitochondria in a sigmoidal concentration-dependent manner in the absence of Cs2+ (Hill coefficient 2.3 +/- 0.2) but does not change K0.5ca2+ nor the maximal mitochondrial activity. Ca2+ concentrations higher than 300 nM are inhibitory at all tested substrate concentrations. Mitochondria from ob/ob mice showed no functional defect when compared with normal controls. It is concluded that activation of the glycerol phosphate shuttle may not be the main coupling site for glucose-induced insulin release at maximal cytoplasmic Ca2+ levels.
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- Ali L., Grapengiesser E., Gylfe E., Hellman B., Lund P. E. Free and bound sodium in pancreatic beta-cells exposed to glucose and tolbutamide. Biochem Biophys Res Commun. 1989 Oct 16;164(1):212–218. doi: 10.1016/0006-291x(89)91704-x. [DOI] [PubMed] [Google Scholar]
- Ashcroft F. M. Adenosine 5'-triphosphate-sensitive potassium channels. Annu Rev Neurosci. 1988;11:97–118. doi: 10.1146/annurev.ne.11.030188.000525. [DOI] [PubMed] [Google Scholar]
- Brown L. J., MacDonald M. J., Lehn D. A., Moran S. M. Sequence of rat mitochondrial glycerol-3-phosphate dehydrogenase cDNA. Evidence for EF-hand calcium-binding domains. J Biol Chem. 1994 May 20;269(20):14363–14366. [PubMed] [Google Scholar]
- Grapengiesser E., Gylfe E., Hellman B. Glucose-induced oscillations of cytoplasmic Ca2+ in the pancreatic beta-cell. Biochem Biophys Res Commun. 1988 Mar 30;151(3):1299–1304. doi: 10.1016/s0006-291x(88)80503-5. [DOI] [PubMed] [Google Scholar]
- Grapengiesser E., Gylfe E., Hellman B. Three types of cytoplasmic Ca2+ oscillations in stimulated pancreatic beta-cells. Arch Biochem Biophys. 1989 Jan;268(1):404–407. doi: 10.1016/0003-9861(89)90602-4. [DOI] [PubMed] [Google Scholar]
- Grynkiewicz G., Poenie M., Tsien R. Y. A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem. 1985 Mar 25;260(6):3440–3450. [PubMed] [Google Scholar]
- Gunter T. E., Pfeiffer D. R. Mechanisms by which mitochondria transport calcium. Am J Physiol. 1990 May;258(5 Pt 1):C755–C786. doi: 10.1152/ajpcell.1990.258.5.C755. [DOI] [PubMed] [Google Scholar]
- Hellman B., Idahl L. A., Danielsson A. Adenosine triphosphate levels of mammalian pancreatic B cells after stimulation with glucose and hypoglycemic sulfonylureas. Diabetes. 1969 Aug;18(8):509–516. doi: 10.2337/diab.18.8.509. [DOI] [PubMed] [Google Scholar]
- Hellman B., Idahl L. A., Lernmark A., Sehlin J., Täljedal I. B. The pancreatic beta-cell recognition of insulin secretagogues. Comparisons of glucose with glyceraldehyde isomers and dihydroxyacetone. Arch Biochem Biophys. 1974 Jun;162(2):448–457. doi: 10.1016/0003-9861(74)90204-5. [DOI] [PubMed] [Google Scholar]
- Hellman B., Idahl L. A., Lernmark A., Sehlin J., Täljedal I. B. The pancreatic beta-cell recognition of insulin secretagogues. Effects of calcium and sodium on glucose metabolism and insulin release. Biochem J. 1974 Jan;138(1):33–45. doi: 10.1042/bj1380033. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hellman B., Idahl L. A., Sehlin J., Täljedal I. B. Influence of anoxia on glucose metabolism in pancreatic islets: lack of correlation between fructose-1,6-diphosphate and apparent glycolytic flux. Diabetologia. 1975 Dec;11(6):495–500. doi: 10.1007/BF01222098. [DOI] [PubMed] [Google Scholar]
- Hellman B. Studies in obese-hyperglycemic mice. Ann N Y Acad Sci. 1965 Oct 8;131(1):541–558. doi: 10.1111/j.1749-6632.1965.tb34819.x. [DOI] [PubMed] [Google Scholar]
- Igbavboa U., Pfeiffer D. R. EGTA inhibits reverse uniport-dependent Ca2+ release from uncoupled mitochondria. Possible regulation of the Ca2+ uniporter by a Ca2+ binding site on the cytoplasmic side of the inner membrane. J Biol Chem. 1988 Jan 25;263(3):1405–1412. [PubMed] [Google Scholar]
- Johansson H., Larsson R., Nygren P., Lindh E., Rastad J., Akerström G., Gylfe E. Cytoplasmic Ca2+ concentration of single normal human and bovine parathyroid cells measured by dual wavelength microfluorometry. Biosci Rep. 1987 Sep;7(9):705–712. doi: 10.1007/BF01116863. [DOI] [PubMed] [Google Scholar]
- Lacy P. E., Kostianovsky M. Method for the isolation of intact islets of Langerhans from the rat pancreas. Diabetes. 1967 Jan;16(1):35–39. doi: 10.2337/diab.16.1.35. [DOI] [PubMed] [Google Scholar]
- Lembert N., Idahl L. A. Regulatory effects of ATP and luciferin on firefly luciferase activity. Biochem J. 1995 Feb 1;305(Pt 3):929–933. doi: 10.1042/bj3050929. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MacDonald M. J. Calcium activation of pancreatic islet mitochondrial glycerol phosphate dehydrogenase. Horm Metab Res. 1982 Dec;14(12):678–679. doi: 10.1055/s-2007-1019117. [DOI] [PubMed] [Google Scholar]
- MacDonald M. J. High content of mitochondrial glycerol-3-phosphate dehydrogenase in pancreatic islets and its inhibition by diazoxide. J Biol Chem. 1981 Aug 25;256(16):8287–8290. [PubMed] [Google Scholar]
- Malaisse W. J. Glucose-sensing by the pancreatic B-cell: the mitochondrial part. Int J Biochem. 1992 May;24(5):693–701. doi: 10.1016/0020-711x(92)90002-i. [DOI] [PubMed] [Google Scholar]
- Matschinsky F. M., Ghosh A. K., Meglasson M. D., Prentki M., June V., von Allman D. Metabolic concomitants in pure, pancreatic beta cells during glucose-stimulated insulin secretion. J Biol Chem. 1986 Oct 25;261(30):14057–14061. [PubMed] [Google Scholar]
- McCormack J. G. Characterization of the effects of Ca2+ on the intramitochondrial Ca2+-sensitive enzymes from rat liver and within intact rat liver mitochondria. Biochem J. 1985 Nov 1;231(3):581–595. doi: 10.1042/bj2310581. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McCormack J. G., Halestrap A. P., Denton R. M. Role of calcium ions in regulation of mammalian intramitochondrial metabolism. Physiol Rev. 1990 Apr;70(2):391–425. doi: 10.1152/physrev.1990.70.2.391. [DOI] [PubMed] [Google Scholar]
- Meissner H. P., Henquin J. C., Preissler M. Potassium dependence of the membrane potential of pancreatic B-cells. FEBS Lett. 1978 Oct 1;94(1):87–89. doi: 10.1016/0014-5793(78)80912-0. [DOI] [PubMed] [Google Scholar]
- Pershadsingh H. A., McDonald J. M. A high affinity calcium-stimulated magnesium-dependent adenosine triphosphatase in rat adipocyte plasma membranes. J Biol Chem. 1980 May 10;255(9):4087–4093. [PubMed] [Google Scholar]
- Rasschaert J., Malaisse W. J. Hexose metabolism in pancreatic islets. Glucose-induced and Ca(2+)-dependent activation of FAD-glycerophosphate dehydrogenase. Biochem J. 1991 Sep 1;278(Pt 2):335–340. doi: 10.1042/bj2780335. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rutter G. A., Pralong W. F., Wollheim C. B. Regulation of mitochondrial glycerol-phosphate dehydrogenase by Ca2+ within electropermeabilized insulin-secreting cells (INS-1). Biochim Biophys Acta. 1992 Dec 15;1175(1):107–113. doi: 10.1016/0167-4889(92)90016-5. [DOI] [PubMed] [Google Scholar]
- Sehlin J., Täljedal I. B. Sodium uptake by microdissected pancreatic islets: effects of ouabain and chloromercuribenzene-p-sulphonic acid. FEBS Lett. 1974 Feb 15;39(2):209–213. doi: 10.1016/0014-5793(74)80052-9. [DOI] [PubMed] [Google Scholar]
- Wibom R., Lundin A., Hultman E. A sensitive method for measuring ATP-formation in rat muscle mitochondria. Scand J Clin Lab Invest. 1990 Apr;50(2):143–152. doi: 10.1080/00365519009089146. [DOI] [PubMed] [Google Scholar]