PARENT SESSION
WA1 - Bioavailability
Chair: Griscom, Sara1, 1 48 Main Street, Southborough, MA
8:00 AM to 12:00 PM - Wednesday, 20 November 2002
Room Ballroom G-I
(493) An in vitro Method for the Determination of Intestinal Absorption of Cadmium from Food by Human cells (Caco-2).
Waisberg, Michael*,1, Hale, Beverly1, Black, Willian1,2, 1 University of Guelph / Dept. of Land Resource Science, Guelph, Ontario, Canada2 University of Guelph / Dept. of Biomedical Sciences, Guelph, Ontario, Canada
ABSTRACT- Cadmium is a heavy metal member of group IIb in the periodic table, which is present in soils, sediments, air and water. Because food constitutes the principal source of cadmium for non-smokers, and food differ in cadmium bioavailability, an in vitro method to study the intestinal uptake of cadmium from food would be very useful. Classicaly, in vivo studies are performed for this purpose but these are time consuming and the public is getting increasingly more concerned with animal utilization. Therefore, our method is based on an in vitro digestion, which simulates the stomachal (using pepsin at pH 2) and intestinal (using pancreatin and bile extract at pH 5) phases of the digestion, followed by the exposure of a cell monolayer of human derived intestinal cells (Caco-2), grown in flasks, which are harvested and analysed by GF-AAS. Currently, we are using lettuce grown hydroponically as our food model and we are also investigating the effect of cadmium incorporation x foliar treatment in the lettuce in relation to the availability of it to cellular uptake. Preliminary data indicates that less Cd incorporated into lettuce during growth is extracted during the digestion, but is more absorbable by the Caco-2 cells, relative to Cd that is added to lettuce, before digestion as a soluble salt. Thus, the bioavailability of plant-incorporated Cd to intestines cannot be reliably estimated from in vitro digestion or extraction alone.
Key words: Cadmium, caco-2, bioavailability, digestion