Intestinal absorption and retention of /sup 109/Cd: effects of cholecalciferol, calcium status and other variables
The intestinal absorption of /sup 109/Cd by chicks was investigated as a function of the site of absorption, absorption period, concentration of stable cadmium, or calcium in the dose, and nutritional status with respect to dietary cholecalciferol, calcium, and phosphorus. All absorption studies utilized the in situ ligated loop technique, and the following observations were made; (a) Duodenal absorption of /sup 109/Cd was approximately 3-fold greater than that in the jejunum or the ileum, with no difference between the latter two. (b) Cadmium absorption in the duodenum occurred in two phases, at an initial rapid rate during the first 20 minutes of absorption, followed by a slow phase thereafter. (c) /sup 109/Cd absorption increased in response to increasing levels of stable Cd in the dosing solution with no evidence for saturation, suggesting that Cd ions may directly affect the permeability characteristics of the epithelial membranes. (d) The absorption of /sup 109/Cd was significantly depressed by 25 mM calcium when present in the ligated loop with a low concentration of cadmium (0.1 mM). However, the absorption was enhanced by the same concentration of calcium when the cadmium concentration in the dose was increased to 1.0 mM. (e) The administration of a single dose of 500 IU of cholecalciferol produced a significant enhancement in /sup 109/Cd absorption. Absorption of /sup 109/Cd was also significantly elevated by dietary calcium or phosphorus deficiency. Nevertheless, a direct involvement of vitamin D-dependent CaBP in cadmium absorption was not indicated as shown by the lack of correlation between the two parameters. (f) The retention of orally administered /sup 109/Cd in the whole body and the gastrointestinal tract diminished with exposure to increasing dietary cadmium.
- Research Organization:
- Cornell Univ., Ithaca, NY
- DOE Contract Number:
- EY-76-S-02-2792
- OSTI ID:
- 6866130
- Journal Information:
- J. Nutr.; (United States), Vol. 108:11
- Country of Publication:
- United States
- Language:
- English
Similar Records
Gastrointestinal absorption of lead in chicks: involvement of the cholecalciferol endocrine system
Stimulation of a Cd-binding protein, and inhibition of the vitamin D-dependent calcium-binding protein, by zinc or cadmium in organ-cultured embryonic chick duodenum
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
CADMIUM 109
INTESTINAL ABSORPTION
CALCIUM
BIOLOGICAL EFFECTS
CHOLECALCIFEROL
PHOSPHORUS
CHICKENS
DOSE-RESPONSE RELATIONSHIPS
NUTRITIONAL DEFICIENCY
RADIONUCLIDE KINETICS
RESPONSE MODIFYING FACTORS
RETENTION
ABSORPTION
ALKALINE EARTH METALS
ANIMALS
BETA DECAY RADIOISOTOPES
BIRDS
CADMIUM ISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
EVEN-ODD NUCLEI
FOWL
INTERMEDIATE MASS NUCLEI
ISOTOPES
METALS
NONMETALS
NUCLEI
RADIOISOTOPES
UPTAKE
VERTEBRATES
VITAMIN D
VITAMINS
YEARS LIVING RADIOISOTOPES
560172* - Radiation Effects- Nuclide Kinetics & Toxicology- Animals- (-1987)
551001 - Physiological Systems- Tracer Techniques