Absorption of Ca45 and Sr85 from Solid and Liquid Food at Various Levels of the Alimentary Tract of the Rat

Casein phosphopeptide (CPP) enhances calcium absorption from the ligated segment of rat small intestine.

“…However, the amount of calcium staying in soluble form was higher when calcium chloride and phosphate were mixed in the presence of CPP than in the presence of SPP. Furthermore, in the presence of SPP , further In both calcium absorption experiments (Expts, 1 and 3) , the ligated ileal loops were preferred, since CPPs increased soluble calcium in the ileum where the passive form of calcium transport is dominant (13) and where the bulk of calcium may be absorbed (14,15). An increased amount of soluble calcium in the lower portion of small intestine must therefore be favorable for calcium absorption .…”

Different effects of bile and sodium taurocholate on mucosal calcium accumulation and calcium absorption in rats.

“…The proximal intestine, i.e., duodenum, is known to exhibit the highest rate of calcium absorption. However, under normal physiological condition, the transit time in the duodenum is faster than that in the more distal segment (23). As shown in Fig, 1, after an intragastric administration of labeled test solution, the mucosal 45Ca content of the duodenum (Ca efflux) at 30 min, showed a tendency to increase in both experimental groups but the changes were not significant.…”

“…This partly reflect ed the type of calcium transport affected, i.e., passive or energy-independent trans port, which is predominant in the jejunum (22). This marked increase in mucosal calcium may also be explained by a longer transit time in the jejunum as com pared to the transit through the duodenum (23) in the in vivo condition.…”

Bioactive Casein Phosphopeptides in Dairy Products as Nutraceuticals for Functional Foods

“…The results from in vivo studies are still too controversial, as there are many factors affecting Ca availability, such as the various co-present dietary compounds in the intestinal lumen [55]. Despite the vigor of the saturable active transport process by the duodenum, most of the absorption of ingested calcium occurs in the ileum (88% of calcium), jejunum (4%) and duodenum (8%) [56]. An important factor determining the contribution of the ileum to overall calcium absorption is the relatively long transit time of calcium in the segments of the small intestine, accounting for approximately 102 min in the ileum and 6 min in the duodenum [57].…”