ISSN:
1432-2013
Keywords:
Sorbitol
;
d-Alanine
;
Ca uptake
;
Ileal cells ATP
;
Ca channel blockers
;
Calmodulin antagonists
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The effect of sorbitol on Ca uptake by isolated ileal epithelial cells was investigated. Intestinal cells were isolated from rat ileum by mechanical vibration.45Ca uptake was approximately 2 times higher in cells exposed to 200 mM sorbitol ofd-alanine than in control cells. This enhancing effect of sorbitol on percentage Ca uptake decreased with increasing Ca concentrations in the incubation medium suggesting an effect on Ca entry velocity. The addition of 10 μM nifedipine or 200 μM verapamil to the incubation medium was devoid of any effect on Ca uptake in ileal cells, whereas 100 μM trifluoperazine or chlorpromazine abolished the stimulatory effect of sorbitol. Finally, the effect of sorbitol on isolated cells was independent of a measurable change of cellular ATP content. In conclusion, the stimulatory effect of sorbitol on ileal Ca uptake is probably exerted through mechanisms other than an increase in intracellular ATP concentration. Sorbitol may enhance enterocyte Ca transport via a direct interaction with calmodulin and/or the Ca pump. It may also exert its effect through an inhibition of the basolateral Na Ca exchanger.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00704151
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