Inhibition of intestinal calcium uptake by cadmium and the effect of a low calcium diet on cadmium retention

Journal Article · Sat Apr 01 04:00:00 EST 1978 · Environ. Res.; (United States)

DOI:https://doi.org/10.1016/0013-9351(78)90094-4· OSTI ID:6661567

Hamilton, D L; Smith, M W

The direct effect of cadmium (Cd) on the in vitro uptake of calcium by rat duodenum was examined by incubating mucosal tissue for 1 to 5 min in an isotonic medium containing /sup 45/Ca with (/sup 3/H) inulin included to correct for calcium (Ca) uptake associated with the space accessible to inulin. Cadmium inhibited a second phase, time-dependent uptake of Ca which is influenced by vitamin D status and dietary levels of calcium. Cadmium had no effect on either an initial rapid uptake of Ca (this is complete within one min) or the inulin space of the intestinal mucosa. Kinetic analysis of the Cd inhibition using 1.0 and 3.0 mM Ca against 0.0--1.0 mM Cd demonstrated Cd was a noncompetitive inhibitor with a k/sub i/ of 0.8 mM. Alternatively, Ca did not inhibit /sup 115m/Cd uptake in animals fed a normal diet. Furthermore, in animals fed a diet low in Ca for seven days, Cd uptake was not affected despite an increased Ca uptake. Whole-body retention and distribution studies of /sup 115m/Cd demonstrated that young rats pair-fed a low Ca diet for seven days retained more /sup 115m/Cd for nine days from a single oral dose of 100 nmol of CdCl/sub 2/ than control animals fed a Ca replete diet. The low Ca diet influenced organ distribution causing more Cd to be retained in the small intestine and kidneys. However, there was no significant change in the sum of the total Cd content in the kidney and liver which are the major sequestering organs of absorbed Cd.

• Research Organization: Inst. of Animal Physiology, Babraham, Eng.
• OSTI ID: 6661567
• Journal Information: Environ. Res.; (United States), Journal Name: Environ. Res.; (United States) Vol. 15:2; ISSN ENVRA
• Country of Publication: United States
• Language: English

Related Subjects

550500* -- Metabolism
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL LOCALIZATION
BODY
CADMIUM 115
CADMIUM CHLORIDES
CADMIUM COMPOUNDS
CADMIUM HALIDES
CADMIUM ISOTOPES
CALCIUM 45
CALCIUM ISOTOPES
CARBOHYDRATES
CHLORIDES
CHLORINE COMPOUNDS
DAYS LIVING RADIOISOTOPES
DIET
DIGESTIVE SYSTEM
EVEN-ODD NUCLEI
GASTROINTESTINAL TRACT
GLANDS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN ISOTOPES
IN VITRO
INGESTION
INHIBITION
INTAKE
INTERMEDIATE MASS NUCLEI
INTESTINES
INULIN
ISOTOPE APPLICATIONS
ISOTOPES
KIDNEYS
KINETICS
LIGHT NUCLEI
LIVER
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
POLYSACCHARIDES
RADIOISOTOPES
RATS
RETENTION
RODENTS
SACCHARIDES
TRACER TECHNIQUES
TRITIUM
UPTAKE
VERTEBRATES
VITAMIN D
VITAMINS
YEARS LIVING RADIOISOTOPES