Glucose-stimulated calcium dynamics in Islets of Langerhans in acute mouse pancreas tissue slices

Andraž Stožer (Author), Jurij Dolenšek (Author), Marjan Rupnik (Author)

Abstract

In endocrine cells within islets of Langerhans calcium ions couple cell stimulation to hormone secretion. Since the advent of modern fluorimetry, numerous in vitro studies employing primarily isolated mouse islets have investigated the effects of various secretagogues on cytoplasmic calcium, predominantly in insulin-secreting beta cells. Due to technical limitations, insights of these studies are inherently limited to a rather small subpopulation of outermost cells. The results also seem to depend on various factors, like culture conditions and duration, and are not always easily reconcilable with findings in vivo. The main controversies regard the types ofcalcium oscillations, presence of calcium waves, and the level of synchronized activity. Here, we set out to combine the in situ acute mouse pancreas tissue slice preparation with noninvasive fluorescent calcium labeling and subsequent confocal laser scanning microscopy to shed new light on the existing controversies utilizing an innovative approach enabling the characterization of responses in many cells from all layers of islets. Our experiments reproducibly showed stable fast calcium oscillations on a sustained plateau rather than slow oscillations as the predominant type of response in acute tissue slices, and that calcium waves are the mechanistic substrate for synchronization of oscillations. We also found indirect evidencethat even a large amplitude calcium signal was not sufficient and thatmetabolic activation was necessary to ensure cell synchronization upon stimulation with glucose. Our novel method helped resolve existing controversies and showed the potential to help answer important physiological questions, making it one of the methods of choice for the foreseeable future.

Keywords

glucose;pancreas;islets of Langerhans;mice;

Data

Language:	English
Year of publishing:	2013
Typology:	1.01 - Original Scientific Article
Organization:	UM MF - Faculty of Medicine
UDC:	612.349.7
COBISS:	512254008
ISSN:	1932-6203
Views:	983
Downloads:	333
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	Pancreas;physiology;Islets of Langerhans;
URN:	URN:SI:UM:
Type (COBISS):	Scientific work
Pages:	str. 1-13
Volume:	ǂVol. ǂ8
Issue:	ǂiss. ǂ1
Chronology:	2013
DOI:	10.1371/journal.pone.0054638
ID:	1439885