Electrophysiological evidence for coupling between β cells of pancreatic islets

Meissner, Hp.

doi:10.1038/262502a0

Cited by 172 publications

(117 citation statements)

References 7 publications

Supporting

Mentioning

113

Contrasting

Order By: Relevance

“…It is well established that electrical activity within a mouse pancreatic islet is synchronized (Meissner 1976;Eddlestone et al 1984;Mears et al 1995) and results in coordinated oscillations in [Ca 2C ] i across the islet (Valdeolmillos et al 1989;Santos et al 1991). Cell coupling has been proposed to explain the synchronization of b-cell electrical activity (Meda et al 1986;Charollais et al 2000), but it is also possible that signalling by autocrine and paracrine factors is involved (Salehi et al 2005).…”

Section: Discussionmentioning

confidence: 99%

“…Evidence for electrical coupling via gap junctions between islet cells has previously been provided by electron microscopy (Orci et al 1975), recordings of membrane potential and currents using sharp intracellular electrodes (Meissner 1976;Eddlestone et al 1984;Mears et al 1995), patch-clamp experiments on isolated islet cell pairs (Perez-Armendariz et al 1991) and dye coupling (Michaels & Sheridan 1981;Charollais et al 2000). It has in fact been proposed that the b-cells function as a 'secretory syncytium' (Santos et al 1991).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cell coupling in mouse pancreatic β-cells measured in intact islets of Langerhans

Zhang

Galvanovskis

Abdulkader

et al. 2008

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

The perforated whole-cell configuration of the patch-clamp technique was applied to functionally identified b-cells in intact mouse pancreatic islets to study the extent of cell coupling between adjacent b-cells. Using a combination of current-and voltage-clamp recordings, the total gap junctional conductance between b-cells in an islet was estimated to be 1.22 nS. The analysis of the current waveforms in a voltage-clamped cell (due to the firing of an action potential in a neighbouring cell) suggested that the gap junctional conductance between a pair of b-cells was 0.17 nS. Subthreshold voltage-clamp depolarization (to K55 mV) gave rise to a slow capacitive current indicative of coupling between b-cells, but not in non-b-cells, with a time constant of 13.5 ms and a total charge movement of 0.2 pC. Our data suggest that a superficial b-cell in an islet is in electrical contact with six to seven other b-cells. No evidence for dye coupling was obtained when cells were dialysed with Lucifer yellow even when electrical coupling was apparent. The correction of the measured resting conductance for the contribution of the gap junctional conductance indicated that the whole-cell K ATP channel conductance (G K,ATP ) falls from approximately 2.5 nS in the absence of glucose to 0.1 nS at 15 mM glucose with an estimated IC 50 of approximately 4 mM. Theoretical considerations indicate that the coupling between b-cells within the islet is sufficient to allow propagation of [Ca 2C ] i waves to spread with a speed of approximately 80 mm s K1 , similar to that observed experimentally in confocal [Ca 2C ] i imaging.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Cell coupling in mouse pancreatic β-cells measured in intact islets of Langerhans

Zhang

Galvanovskis

Abdulkader

et al. 2008

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

show abstract

“…This cell population has also got a common and coordinate pulsatile release pattern of insulin [102,105,119,125], and therefore intra-islet coordination of release from the individual beta cells must occur. This coordination could be through electro-physiological coupling among beta cells [126]. Studies on intracellular calcium show that an intra-islet spreading of the calcium influx is observed following an increase in intracellular calcium in a beta cell [104,127,128].…”

Section: Contribution Of Pulsatile Insulin Release To the Overall Insmentioning

confidence: 99%

The in vivo regulation of pulsatile insulin secretion

2002

View full text Add to dashboard Cite

In 1922, Karen Hansen [1] measured two series of blood glucose concentrations and reported oscillations in the peripheral concentrations of this substrate, results which were validated by simultaneous sampling from two sites to exclude the possibility that assay variability was a cause of the observed variations. Furthermore she studied the glucose concentrations in diabetic patients, and described both rapid and slower oscillations [1]. Half a century later the observation of rapid oscillations was shown to correlate with oscillations in the peripheral insulin concentrations [2±6], with glucose concentration increases slightly out of phase with insulin secretion pulses [7]. The pulsatile secretion of insulin was shown to coincide with islet pulsatile release of glucagon [4,6,8,9], and somatostatin [9±11]. A number of studies have reported importance of this release pattern for optimal insulin action [10, 12±21, 21±25], for overall insulin secretion [26±35], and for possible development of disease [36±43]. Studies on pulsatile insulin secretion could therefore be important for appreciating how insulin release is regulated overall and how Diabetologia (2002) 45: 3±20 ReviewsThe in vivo regulation of pulsatile insulin secretion

show abstract

“…25 Electrical coupling between islet cells has previously been shown to be dependent on gap junctions. [26][27][28][29] Some time ago, it was proposed that gap junctions synchronize electrical activity and secretion in b-cells in distinct sections of the islet. 28 More recently it was shown that a single b-cell in an islet is in electrical contact with six to seven other β-cells.…”

Section: Cellular Models Of Insulin Secretion and Pseudoisletsmentioning

confidence: 99%