Effect of vitamin D on the intestinal absorption of /sup 203/Pb and /sup 47/Ca in chicks
The transfer of /sup 203/Pb and/or /sup 47/Ca across the intestinal epithelium of the chick was investigated, with emphasis given to the functional role of cholecalciferol (vitamin D-3). /sup 203/Pb, after introduction in the intestinal lumen, is rapidly accumulated by the intestinal tissue, and only a fraction of /sup 203/ Pb is translocated parenterally (absorbed). Cholecalciferol did not significantly affect the accumulation of /sup 203/Pb by intestinal tissue but did accelerate /sup 203/Pb movement across the basal-lateral membrane. In contrast, cholecalciferol both decreased /sup 47/Ca tissue levels and increased /sup 47/Ca absorption. In rachitic chicks, the rate of absorption of /sup 203/Pb was greater in the distal than in the proximal segments of the intestine; after cholecalciferol repletion, the degree of absorption in all segments was similar, indicating the order of cholecalciferol effectiveness as duodenum greater than or equal to jejunum > ileum. An acute dose of 1,25(OH)/sub 2/D/sub 3/ to rachitic chicks also enhanced both /sup 203/Pb and /sup 47/Ca absorption, but the time course and pattern of absorption of these metal cations differed. The time at which the absorption of /sup 203/Pb peaked and returned to base-line occurred sooner than for /sup 47/Ca. Also the back-flux (blood ..-->.. intestinal lumen) of /sup 47/Ca was enhanced by cholecalciferol, whereas no effect on the back-flux of /sup 203/Pb was noted. These studies show that cholecalciferol and 1,25(OH)/sub 2/D/sub 3/ affects both the /sup 203/Pb and /sup 47/Ca absorptive processes, but the nature of these responses are not identical, suggesting differences in the transport path or the macromolecular interactions of these metal ions during the course of absorption, or both.
- Research Organization:
- Cornell Univ., Ithaca, NY
- DOE Contract Number:
- AC02-76EV02792
- OSTI ID:
- 6093231
- Journal Information:
- J. Nutr.; (United States), Vol. 112:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CALCIUM 47
INTESTINAL ABSORPTION
CHOLECALCIFEROL
BIOLOGICAL EFFECTS
LEAD 203
BIOLOGICAL ACCUMULATION
BIOLOGICAL PATHWAYS
CHICKENS
COMPARATIVE EVALUATIONS
EPITHELIUM
EXPERIMENTAL DATA
RESPONSE MODIFYING FACTORS
RICKETS
VITAMIN D
ABSORPTION
ALKALINE EARTH ISOTOPES
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIRDS
BODY
CALCIUM ISOTOPES
DATA
DAYS LIVING RADIOISOTOPES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
FOWL
HEAVY NUCLEI
INFORMATION
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LEAD ISOTOPES
METABOLIC DISEASES
NUCLEI
NUMERICAL DATA
RADIOISOTOPES
SECONDS LIVING RADIOISOTOPES
SKELETAL DISEASES
TISSUES
UPTAKE
VERTEBRATES
VITAMINS
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)