The effect of glucose upon the handling of22Na+ by pancreatic islets was investigated. Using a triple-isotope technique, the apparent concentration of Na+ in islet cells was estimated at 50–75 mM. The pattern of22Na+ efflux from perifused islets indicates that this intracellular Na+ load is compartmentalized among a small, possibly organelle-bound pool characterized by a low fractional turnover rate (5%/min) and a large, presumably cystosolic pool displaying a much higher fractional turnover rate (20–34%/min). Glucose provokes a rapid, pronounced and sustained increase in the fractional outflow rate of Na+ across the plasma membrane and, under steady-state conditions, moderately reduces the concentration of Na+ inside the islet cells. The glucose-induced increase in Na+ outflow rate, which is also observed in response to glyceraldehyde and does not require the presence of extracellular Ca2+, might be mediated, in part at least, by an ouabain-resistant ionophoretic system. The experimental data suggest that glucose also increases the inward transport of Na+ in islet cells by a veratridine-sensitive channel.
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Aschroft, S. J. H., Weerasinghe, L. C. C., Randle, P. J.: Interrelationships of islet metabolism, adenosine triphosphate content and insulin release. Biochem. J.132, 223–231 (1973)
Baker, P. F., Blaustein, M. P., Hodgkin, A. L., Steinhardt, R. A.: The influence of calcium on sodium efflux in squid axons. J. Physiol. (Lond.)200, 431–458 (1969)
Berman, M., Weiss, M. F.: Users manual of SAAM. Bethesda: N.I.A.M.D. (N.I.H.) 1971
Blaustein, M. P.: The interrelationship between sodium and calcium fluxes across cell membranes. Rev. Physiol. Biochem. Pharmacol.70, 33–82 (1974)
Blaustein, M. P., Russell, J. M.: Sodium-calcium and calcium-calcium exchange in internally dialyzed squid giant axons. J. Membrane Biol.22, 285–312 (1975)
Boschero, A. C., Malaisse, W. J.: Effect of glucose on22Na+ efflux in pancreatic islets. Arch. Int. Physiol. Biochim. in press (1978)
boschero, A. C., Kawazu, S., Duncan, G., Malaisse, W. J.: Effect of glucose on K+ handling by pancreatic islets. FEBS Lett.83, 151–154 (1977)
Brisson, G. R., Malaisse, W. J.: The stimulus-secretion coupling of glucose-induced insulin release. XI. Effect of theophylline and epinephrine on45Ca efflux from perifused islets. Metabolism22, 455–465 (1973)
Brownell, G. L., Berman, M., Robertson, J. S.: Nomenclature of tracer kinetics. Int. J. Appl. Radiat. Isotop.19, 249–269 (1968)
Dean, P. M.: Ultrastructural morphometry of the pancreatic β-cell. Diabetologia9, 115–119 (1973)
Donatsch, P., Lowe, D. A., Richardson, B. P., Tayler, P.: The functional significance of sodium channels in pancreatic beta-cell membranes. J. Physiol. (Lond.)267, 357–376 (1977)
Garrahan, P. J., Glynn, I. M.: The stoichiometry of the sodium pump. J. Physiol. (Lond.)192, 217–235 (1967)
Hales C. N., Milner, R. D. G.: The role of sodium and potassium in insulin secretion from rabbit pancreas. J. Physiol. (Lond.)194, 725–743 (1968)
Hellman, B., Sehlin, J., Täljedal, I.-B.: Evidence for mediated transport of glucose in mammalian pancreatic β-cells. Biochim. Biophys. Acta241, 147–154 (1971)
Hellman, B., Idahl, L.-Å., Lermark, Å., Sehlin, J., Täljedal, I.-B.: The pancreatic β-cell recognition of insulin secretagogues. Comparison of glucose with glyceraldehyde isomers and dihydroxyacetone. Arch. Biochem.162, 448–457 (1974)
Kemmler, W., Löffler, G.: NaK-ATPase in rat pancreatic islets. Diabetologia13, 235–238 (1977)
Lacy, P. E., Kostianovsky, M.: Method for the isolation of intact islets of Langerhans from the rat pancreats. Diabetes6, 35–39 (1967)
Lambert, A. E.: The regulation of insulin secretion. Rev. Physiol. Biochem. Pharmacol.75, 97–159 (1976)
Malaisse, W. J.: Calcium ion fluxes and insulin release in pancreatic islets. Biochem. Soc. Trans.5, 872–875 (1977)
Malaisse, W. J., Brisson, G. R., Baird, L. E.: Stimulus-secretion coupling of glucose-induced insulin release. X. Effect of glucose on45Ca efflux from perifused islets. Am. J. Physiol.224, 389–394 (1973)
Malaisse, W. J., Brisson, G. R., Malaisse-Lagae, F.: The stimulus-secretion coupling of glucose-induced insulin release. I. Interaction of epinephrine and alkaline earth cations. J. Lab. Clin. Med.76, 895–902 (1970)
Malaisse, W. J., Malaisse-Lagae, F., Brisson, G.: The stimulussecretion coupling of glucose-induced insulin release. II. Interaction of alkali and alkaline earth cations. Horm. Metab. Res.3, 65–70 (1971)
Malaisse, W. J., Herchuelz, A., Levy, J., Sener, A., Pipeleers, D. G., Devis, G., Somers, G., Van Obberghen, E.: The stimulussecretion of glucose-induced insulin release. XIX. The insulinotropic effect of glyceraldehyde. Mol. Cell. Endocrinol.4, 1–12 (1976)
Malaisse, W. J., Herchuelz, A., Devis, G., Somers, G., Boschero, A. C., Hutton, J. C., Kawazu, S., Sener, A., Atwater, I. J., Duncan, G., Ribalet, B., Rojas, E.: Regulation of calcium fluxes and their regulatory roles in pancreatic islets. Ann. N.Y. Acad. Sci. (in press, 1978)
Malaisse, W. J., Boschero, A. C., Kawazu, S., Hutton, J. C.: The stimulus-secretion coupling of glucose-induced insulin release. XXVII. Effect of glucose on K+ fluxes in isolated islets. Pflügers Arch.373, 237–242 (1978)
Randle, P. J.: Islet metabolism and insulin secretion. Excerpta Medica I.C.S.231, 232–239 (1971)
Sehlin, J., Täljedal, I.-B.: Sodium uptake by microdissected pancreatic islets: Effects of ouabain and chloromercuribenzene-p-sulphonic acid. FEBS Lett.39, 209–213 (1974)
Sehlin, J., Täljedal, I.-B.: Transport of rubidium and sodium in pancreatic islets. J. Physiol. (Lond.)242, 505–515 (1974)
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Kawazu, S., Boschero, A.C., Delcroix, C. et al. The stimulus-secretion coupling of glucose-induced insulin release. Pflugers Arch. 375, 197–206 (1978). https://doi.org/10.1007/BF00584244
- Pancreatic islets