Effects of proteins on absorption by the rat of iron from polymeric and low-molecular-weight iron species
To examine effects of proteins on Fe absorption from polymeric ferric hydroxides (polys) or low-molecular-weight complexes (LMW Fe), 2 studies were conducted. First, anemic rats were given /sup 59/Fe-labeled polys or LMW Fe in the presence and absence of pepsin-digested soy protein isolate, casein, and BSA. The doses were introduced into ligated duodenal segments for 1 hr. Uptake into the carcass of /sup 59/Fe from polys was doubled in the presence of BSA (7.8 vs 16.1%, p < .05) while casein and soy had no effect (5.5 and 6.5%). Absorption of /sup 59/Fe from LMW Fe was 7X greater than from polys; BSA and casein had no effect but soy depressed Fe uptake by almost 50% (57.4 vs 35.5%, p < .05). The second experiment repeated the first except that the proteins were not pepsin-digested and the doses were given by gastric intubation. All Fe, whether from polys or LMW Fe, was highly available (although in vitro digestions reveal that polys are not depolymerized to a large degree under simulated stomach conditions). Soy depressed Fe uptake from both sources (92.9 vs. 81.6%, LMW Fe and 85.4 vs 73.7%, polys) while casein and BSA had no effect. These results show: (1) BSA can depolymerize polys in the rat duodenum, thus enhancing absorption; (2) soy isolate generally depressed Fe uptake; and (3) the rat stomach appears to have an exceptional capacity for equalizing Fe sources.
- Research Organization:
- Cornell Univ., Ithaca, NY
- OSTI ID:
- 7188895
- Report Number(s):
- CONF-8604222-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:4; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
IRON
INTESTINAL ABSORPTION
PROTEINS
BIOLOGICAL EFFECTS
CASEIN
IRON 59
MOLECULAR WEIGHT
RATS
TRACER TECHNIQUES
ABSORPTION
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
ELEMENTS
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
IRON ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
METALS
NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
RADIOISOTOPES
RODENTS
TRANSITION ELEMENTS
UPTAKE
VERTEBRATES
550501* - Metabolism- Tracer Techniques