Absorption and transport of milk calcium by infant rats

Journal Article · Fri Jan 01 00:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:7189678

Blake, H H; Henning, S J ^[1]

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1. Univ. of Houston, TX (USA)

All previous studies of Ca absorption in the developing animal have used simple salts of Ca. The aims of the current study are (1) to determine the predominant form of Ca in rat milk and (2) to compare the absorption of milk Ca and CaCl{sub 2}. In vivo-labeled rat milk was obtained by injecting lactating dams with {sup 45}CaCl{sub 2}. Distribution of {sup 45}Ca in the cream, whey, and casein fractions was determined by differential centrifugation, the values being 0.3, 5, and 95%, respectively. To study Ca absorption, rats aged 14 and 28 days received either {sup 45}Ca-milk or {sup 45}CaCl{sub 2} by intragastric intubation. At 14 days, transport of milk Ca into the carcass was significantly slower than that of CaCl{sub 2}, although by 6 h postintubation both had plateaued at {approximately}92% of dose. At 28 days, the time course of transport was the same for the two forms of Ca, and the plateau was not significantly different from that at 14 days. In the younger animals, more Ca from milk than from CaCl{sub 2} was retained in gastrointestinal tissue. Quantitation of {sup 45}Ca in various segments of the gastrointestinal tract showed that the greater retention of milk Ca occurred in the stomach, the duodenum, and the distal jejunum. The authors conclude that milk Ca is efficiently absorbed by the suckling rat, possibly in a protein-bound form. The mechanism of the absorptive process awaits further investigation.

• OSTI ID: 7189678
• Journal Information: American Journal of Physiology; (USA), Vol. 254:1; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
CALCIUM 45
INTESTINAL ABSORPTION
GASTROINTESTINAL TRACT
RADIONUCLIDE KINETICS
NEONATES
RADIATION DOSES
AGE DEPENDENCE
CALCIUM CHLORIDES
LACTATION
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SMALL INTESTINE
ABSORPTION
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BODY
BODY FLUIDS
CALCIUM COMPOUNDS
CALCIUM HALIDES
CALCIUM ISOTOPES
CHLORIDES
CHLORINE COMPOUNDS
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DOSES
EVEN-ODD NUCLEI
FOOD
HALIDES
HALOGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
INTESTINES
ISOTOPES
MAMMALS
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ORGANS
RADIOISOTOPES
RODENTS
UPTAKE
VERTEBRATES
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& Toxicology
551001 - Physiological Systems- Tracer Techniques