Ebook: Biophysics of the Pancreatic β-Cell

Pancreatic a-cell biophysics has undergone a veritable informa­ tion explosion in the past two years. Single channel and macroscopic currents have become easily accessible following the introduction of the patch clamp technique. In addition to this new approach, further development of techniques for optical measurements, ion-sensitive microelectrodes, permeabilized cells and mathematical modelling have recently added to the now classical techniques of membrane potential recording and tracer flux measurement. The International Workshop on Biophysics of the Pancreatic a-Cell held in Alicante (Spain) on Sep­ tember 30 - October 1, 1985, has now given us the opportunity to share experiences with these new techniques applied to the a-cell. Further­ more this was the first occasion for most of the groups doing patch­ clamp studies of the a-cell to decide on appropriate nomenclature and to debate the different characteristics of the a-cell ionic channels. To make this information available to the larger scientific community a record of the meeting has been assembled in this book. It is a collection of research papers by leading scientists at the meet­ ing working on biophysical, biochemical and physiological aspects. of secretion. We grouped their contributions in seven sections, includ­ ing new experimental approaches, K-channels, Ca-channels, role of ionic channels, intracellular ionized calcium, neural regulation and mechanisms of insulin release. Each section gives an account of the state of the problem at the time of the meeting, and the subjects are analyzed from the different perspectives of the various contributors.

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Content:
Front Matter....Pages i-xii
Patch Pipettes Used for Loading Small Cells with Fluorescent Indicator Dyes....Pages 1-5
Optical Detection of Calcium Dependent ATP Release from Stimulated Medullary Chromaffin Cells....Pages 7-29
Glucose-Evoked Changes in [K+] and [Ca2+] in the Intercellular Spaces of the Mouse Islet of Langerhans....Pages 31-51
A Potassium Channel Modulated by Glucose Metabolism in Rat Pancreatic ?-Cells....Pages 53-62
Glucose Suppresses ATP-Inhibited K-Channels in Pancreatic ?-Cells....Pages 63-67
K-Channels in an Insulin-Secreting Cell Line: Effects of ATP and Sulphonylureas....Pages 69-76
Inhibition of K-Channels in Insulin Secreting Cells....Pages 77-82
Pharmacological Control of 86Rb Efflux from Mouse Pancreatic Islets....Pages 83-93
Electrophysiological Measurements Show Marked Differences in the Properties of the Pancreatic ?-Cell K-Channels from Albino Mice and a Strain of ob/ob (Obese) Mice....Pages 95-107
Single K-Channel Activity in Fish Islet Cells....Pages 109-123
Potassium Channels in Adrenocortical and Parathyroid Cells....Pages 125-137
Pharmacological Properties of the Chromaffin Cell Calcium Channel....Pages 139-157
Insulin Release and K+-Induced Depolarization in Mouse Pancreatic ?-Cells....Pages 159-166
Calcium and Potassium Currents Recorded from Pancreatic ?-Cells Under Voltage Clamp Control....Pages 167-175
Voltage-Activated Ca2+ and K+ Currents in an Insulin-Secreting Cell Line (RINm5F)....Pages 177-187
Voltage-Gated Ca Current in Pancreatic Islet ? -Cells....Pages 189-193
Effects of Verapamil and Nifedipine on Glucose-Induced Electrical Activity in Pancreatic ?-Cells....Pages 195-200
Stimulation of Insulin Release by Organic Calcium-Agonists....Pages 201-205
Contribution of Isotope Flux Studies to Understanding the Mechanism of the ?-Cell Membrane....Pages 207-223
The Role of Anions in the Regulation of Insulin Secretion....Pages 225-225
Graded Spike Electrogenesis in Mouse Pancreatic ?-Cells....Pages 227-233
Prediction of the Glucose-Induced Changes in Membrane Ionic Permeability and Cytosolic Ca2+ by Mathematical Modeling....Pages 235-246
Modelling the ?-Cell Electrical Activity....Pages 247-263
Insulin Secretion Studied in Islets Permeabilised by High Voltage Discharge....Pages 265-278
Regulation of Insulin Release Independent of Changes of Cytosolic Ca2+ Concentration....Pages 279-291
The Role of Cytosolic Calcium in Insulin Secretion from a Hamster Beta Cell Line....Pages 293-303
Differential Effect of Nutrient and Non-Nutrient Secretagogues on Cytosolic Free Ca2+ in Pancreatic Islet Cells....Pages 305-316
Relationship between Extracellular Na+ and the Total Ionized Ca2+ Content of Rat Pancreatic Islets....Pages 317-318
Mobilization of Different Pools of Glucose-Incorporated Calcium in Pancreatic ?-Cells after Muscarinic Receptor Activation....Pages 319-323
Effect of the Order of Application of Neural Inputs on Insulin Secretion....Pages 325-341
Muscarinic Receptors and the Control of Glucose-Induced Electrical Activity in the Pancreatic ?-Cell....Pages 343-349
Electrophysiological Evidence for Histaminergic Modulation of Pancreatic ?-Cell Function....Pages 351-358
Effect of Melatonin on Insulin Secretion from Isolated Rat Islets of Langerhans....Pages 359-365
Calcium Regulation of Membrane Fusion during Hormone Secretion....Pages 367-368
The Insulin Secretory Granule: Features and Functions in Common with Other Endocrine Granules....Pages 369-383
Effects of Monensin on Glucose-Induced Insulin Release and 45Ca2+ Outflow....Pages 385-396
Interdependency of Ca2+ Availability and Cyclic AMP Generation in the Pancreatic ?-Cell....Pages 397-401
Cyclic Amp-Antagonist, a Second Messenger for Insulin Action, Inhibits Glucose-Stimulated Insulin Secretion in Isolated Islets of Chinese Hamsters....Pages 403-407
Pulsatile Insulin Release and Electrical Activity from Single ob/ob Mouse Islets of Langerhans....Pages 409-412
Comparision of Stimulus-Secretion Coupling in Normal and ob/ob (Norwich Colony) Mouse Islets of Langerhans....Pages 413-425
Insulin Release, Ca2+ Fluxes and Calmodulin Content of Pancreatic Islets in Aging Rats....Pages 427-427
Protein Carboxyl Methylation in Rat Pancreatic Islets: Possible Role in ?-Cell Function....Pages 429-430
Role of Transglutaminase in Proinsulin Conversion and Insulin Release....Pages 431-442
Induction of the Glucokinase-Glucose Sensor in Pancreatic Islets of Insulinoma-Bearing Rats Following Tumor Removal....Pages 443-446
Biochemical Design Features of the Pancreatic Islet Cell Glucose-Sensory System....Pages 447-457
Back Matter....Pages 459-469
....Pages 471-494