Carbamylcholine- and catecholamine-induced intracellular calcium dynamics of epithelial cells in mouse ileal crypts

The intestinal epithelium is composed of various cells, and the enteric nervous system, which controls the epithelial functions, has different neurotransmitters and/or modulators. The aim of this study was to show whether the responses of intestinal epithelial cells to different neurotransmitters are elicited throughout the entire epithelium or are restricted to a certain cell.

The spatiotemporal dynamics of cytosolic calcium ion ([Ca2+]c) were measured by digital imaging analysis in isolated crypts of mouse ileum loaded with [1-[2-(5'-carboxyoxazol-2'-yl)-6-amino-benzofuran-5- oxy]-2-(2'-amino-5'-methylphenoxy)-ethane-N,N,N',N'-tetraacetic acid] pentakis (acetoxylmethyl) ester. Thereafter, the crypt cells were identified morphologically.

Carbamylcholine elicited [Ca2+]c dynamics in Paneth cells, showing a biphasic increase, but neither cholecystokinin octapeptide nor nicotine had any effect on the [Ca2+]c of the crypt cells including the Paneth cells. Adrenaline and noradrenaline, but not isoproterenol, induced a transient elevation of [Ca2+]c of some enterochromaffin cells. Increases in the [Ca2+]c of most crypt cells were elicited by thapsigargin. Propagation of a [Ca2+]c wave in the crypts was not evident.

Increases in [Ca2+]c can be induced by carbamylcholine in Paneth cells and catecholamines in some enterochromaffin cells. The digital imaging analysis showed the heterogeneity of the responses of intestinal crypt cells to different transmitters.