ISSN:
1432-0878
Keywords:
Intestinal crypt Ca2+ dynamics AlF4– ATP Mouse (ICR, DDY)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract. Previous digital imaging analysis of intracellular calcium ion ([Ca2+]i) dynamics in the crypt of the small intestine showed little response by most columnar cells to cholinergic and adrenergic agonists. The objective of the present study was to demonstrate whether G-protein activators and other transmitters elicit [Ca2+]i changes in crypt cells. We used digital imaging to analyze spatiotemporal dynamics of [Ca2+]i in Fura-2/AM-loaded isolated crypts of mouse duodenum and ileum. AlF4 – increased [Ca2+]i in crypt columnar cells. In many cases, we observed [Ca2+]i oscillations, which were synchronized throughout the entire crypt. The oscillations were blocked by octanol. ATP, but not adenosine, caused a [Ca2+]i increase in middle crypt-regions of the duodenum and upper regions of the ileum, and the [Ca2+]i wave propagated towards the crypt bottom. The ATP-induced [Ca2+]i increase was prevented by pretreatment with thapsigargin or suramin, but not by La3+ or an extracellular Ca2+-free environment. Neither dopamine, 5-hydroxytryptamine (5-HT), histamine, vasoactive intestinal peptide, substance P, cholera toxin, nor guanylin had significant effects. The [Ca2+]i dynamics of Paneth cells were independent of the AlF4 –-induced synchronous oscillations of columnar cells and of the ATP-induced [Ca2+]i wave. In conclusion, crypt columnar cells have [Ca2+]i-dependent intracellular signaling mechanisms that are linked with G proteins, and by which the cells communicate with each other. ATP elicited [Ca2+]i mobilization from columnar cells via P2 receptors, although some regional differences were noted between the duodenum and ileum.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004419900069
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