|
|
|
|
|
|
|
||
Original Article |
patrik.rorsman{at}mphy.lu.se
We have applied the perforated patch whole-cell technique to β cells within intact pancreatic islets to identify the current underlying the glucose-induced rhythmic firing of action potentials. Trains of depolarizations (to simulate glucose-induced electrical activity) resulted in the gradual (time constant: 2.3 s) development of a small (<0.8 nS) K+ conductance. The current was dependent on Ca2+ influx but unaffected by apamin and charybdotoxin, two blockers of Ca2+-activated K+ channels, and was insensitive to tolbutamide (a blocker of ATP-regulated K+ channels) but partially (>60%) blocked by high (10–20 mM) concentrations of tetraethylammonium. Upon cessation of electrical stimulation, the current deactivated exponentially with a time constant of 6.5 s. This is similar to the interval between two successive bursts of action potentials. We propose that this Ca2+-activated K+ current plays an important role in the generation of oscillatory electrical activity in the β cell.
Key Words: insulin • pancreas • Ca2+-activated K+ channel • Ca2+ • membrane potential
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Facebook 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  M. Dufer, B. Gier, D. Wolpers, P. Krippeit-Drews, P. Ruth, and G. Drews Enhanced Glucose Tolerance by SK4 Channel Inhibition in Pancreatic {beta}-Cells Diabetes, August 1, 2009; 58(8): 1835 - 1843. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Zehetner, C. Danzer, S. Collins, K. Eckhardt, P. A. Gerber, P. Ballschmieter, J. Galvanovskis, K. Shimomura, F. M. Ashcroft, B. Thorens, et al. pVHL is a regulator of glucose metabolism and insulin secretion in pancreatic {beta} cells Genes & Dev., November 15, 2008; 22(22): 3135 - 3146. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Q. Zhang, J. Galvanovskis, F. Abdulkader, C. J Partridge, S. O Gopel, L. Eliasson, and P. Rorsman Cell coupling in mouse pancreatic {beta}-cells measured in intact islets of Langerhans Phil Trans R Soc A, October 13, 2008; 366(1880): 3503 - 3523. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Bertram, A. Sherman, and L. S. Satin Metabolic and electrical oscillations: partners in controlling pulsatile insulin secretion Am J Physiol Endocrinol Metab, October 1, 2007; 293(4): E890 - E900. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Fujiwara, F. Maekawa, K. Dezaki, M. Nakata, T. Yashiro, and T. Yada Oleic Acid Glucose-Independently Stimulates Glucagon Secretion by Increasing Cytoplasmic Ca2+ via Endoplasmic Reticulum Ca2+ Release and Ca2+ Influx in the Rat Islet {alpha}-Cells Endocrinology, May 1, 2007; 148(5): 2496 - 2504. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Herrington, Y.-P. Zhou, R. M. Bugianesi, P. M. Dulski, Y. Feng, V. A. Warren, M. M. Smith, M. G. Kohler, V. M. Garsky, M. Sanchez, et al. Blockers of the Delayed-Rectifier Potassium Current in Pancreatic {beta}-Cells Enhance Glucose-Dependent Insulin Secretion. Diabetes, April 1, 2006; 55(4): 1034 - 1042. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Neye, M. Dufer, G. Drews, and P. Krippeit-Drews HIV Protease Inhibitors: Suppression of Insulin Secretion by Inhibition of Voltage-Dependent K+ Currents and Anion Currents J. Pharmacol. Exp. Ther., January 1, 2006; 316(1): 106 - 112. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Zhang, K. Houamed, S. Kupershmidt, D. Roden, and L. S. Satin Pharmacological Properties and Functional Role of Kslow Current in Mouse Pancreatic {beta}-Cells: SK Channels Contribute to Kslow Tail Current and Modulate Insulin Secretion J. Gen. Physiol., September 26, 2005; 126(4): 353 - 363. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Herrington, M. Sanchez, D. Wunderler, L. Yan, R. M Bugianesi, I. E Dick, S. A Clark, R. M Brochu, B. T Priest, M. G Kohler, et al. Biophysical and pharmacological properties of the voltage-gated potassium current of human pancreatic {beta}-cells J. Physiol., August 15, 2005; 567(1): 159 - 175. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. S. Nunemaker, M. Zhang, and L. S. Satin Insulin Feedback Alters Mitochondrial Activity Through an ATP-sensitive K+ Channel-Dependent Pathway in Mouse Islets and {beta}-Cells Diabetes, July 1, 2004; 53(7): 1765 - 1772. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Liu, N. Hilliard, and G. H. Hockerman Cav1.3 Is Preferentially Coupled to Glucose-Induced [Ca2+]i Oscillations in the Pancreatic {beta} Cell Line INS-1 Mol. Pharmacol., May 1, 2004; 65(5): 1269 - 1277. [Abstract] [Full Text]
|
|
|
|
|
|
S. Gopel, Q. Zhang, L. Eliasson, X.-S. Ma, J. Galvanovskis, T. Kanno, A. Salehi, and P. Rorsman Capacitance measurements of exocytosis in mouse pancreatic {alpha}-, {beta}- and {delta}-cells within intact islets of Langerhans J. Physiol., May 1, 2004; 556(3): 711 - 726. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Ashcroft and P. Rorsman Type 2 diabetes mellitus: not quite exciting enough? Hum. Mol. Genet., April 1, 2004; 13(suppl_1): R21 - R31. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Yan, D. J. Figueroa, C. P. Austin, Y. Liu, R. M. Bugianesi, R. S. Slaughter, G. J. Kaczorowski, and M. G. Kohler Expression of Voltage-Gated Potassium Channels in Human and Rhesus Pancreatic Islets Diabetes, March 1, 2004; 53(3): 597 - 607. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. A. Tamarina, Y. Wang, L. Mariotto, A. Kuznetsov, C. Bond, J. Adelman, and L. H. Philipson Small-Conductance Calcium-Activated K+ Channels Are Expressed in Pancreatic Islets and Regulate Glucose Responses Diabetes, August 1, 2003; 52(8): 2000 - 2006. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. E. Fridlyand, N. Tamarina, and L. H. Philipson Modeling of Ca2+ flux in pancreatic {beta}-cells: role of the plasma membrane and intracellular stores Am J Physiol Endocrinol Metab, July 1, 2003; 285(1): E138 - E154. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T Kanno, P Rorsman, and S O Gopel Glucose-dependent regulation of rhythmic action potential firing in pancreatic {beta}-cells by kATP-channel modulation J. Physiol., December 1, 2002; 545(2): 501 - 507. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P.B. Goforth, R. Bertram, F.A. Khan, M. Zhang, A. Sherman, and L.S. Satin Calcium-activated K+ Channels of Mouse {beta}-cells are Controlled by Both Store and Cytoplasmic Ca2+: Experimental and Theoretical Studies J. Gen. Physiol., August 26, 2002; 120(3): 307 - 322. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J.-F. Rolland, J.-C. Henquin, and P. Gilon Feedback Control of the ATP-Sensitive K+ Current by Cytosolic Ca2+ Contributes to Oscillations of the Membrane Potential in Pancreatic {beta}-Cells Diabetes, February 1, 2002; 51(2): 376 - 384. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. E. MacDonald, X. F. Ha, J. Wang, S. R. Smukler, A. M. Sun, H. Y. Gaisano, A. M. F. Salapatek, P. H. Backx, and M. B. Wheeler Members of the Kv1 and Kv2 Voltage-Dependent K+ Channel Families Regulate Insulin Secretion Mol. Endocrinol., August 1, 2001; 15(8): 1423 - 1435. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. ROSATI, P. MARCHETTI, O. CROCIANI, M. LECCHI, R. LUPI, A. ARCANGELI, M. OLIVOTTO, and E. WANKE Glucose- and arginine-induced insulin secretion by human pancreatic {beta}-cells: the role of HERG K+ channels in firing and release FASEB J, December 1, 2000; 14(15): 2601 - 2610. [Abstract] [Full Text]
|
|
|
|
|
|
S O Gopel, T Kanno, S Barg, and P Rorsman Patch-clamp characterisation of somatostatin-secreting {delta}-cells in intact mouse pancreatic islets J. Physiol., November 1, 2000; 528(3): 497 - 507. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S O Gopel, T Kanno, S Barg, X-G Weng, J Gromada, and P Rorsman Regulation of glucagon release in mouse {alpha}-cells by KATP channels and inactivation of TTX-sensitive Na+ channels J. Physiol., November 1, 2000; 528(3): 509 - 520. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Arredouani, J.-C. Henquin, and P. Gilon Contribution of the endoplasmic reticulum to the glucose-induced [Ca2+]c response in mouse pancreatic islets Am J Physiol Endocrinol Metab, May 1, 2002; 282(5): E982 - E991. [Abstract] [Full Text] [PDF]
|
|
|
|
