/sup 54/Mn absorption and excretion in rats fed soy protein and casein diets
Rats were fed diets containing either soy protein or casein and different levels of manganese, methionine, phytic acid, or arginine for 7 days and then fed test meals labeled with 2 microCi of 54Mn after an overnight fast. Retention of 54Mn in each rat was measured every other day for 21 days using a whole-body counter. Liver manganese was higher (P less than 0.0001) in soy protein-fed rats (8.8 micrograms/g) than in casein-fed rats (5.2 micrograms/g); manganese superoxide dismutase activity also was higher in soy protein-fed rats than in casein-fed rats (P less than 0.01). There was a significant interaction between manganese and protein which affected manganese absorption and biologic half-life of 54Mn. In a second experiment, rats fed soy protein-test meals retained more 54Mn (P less than 0.001) than casein-fed rats. Liver manganese (8.3 micrograms/g) in the soy protein group was also higher than that (5.7 micrograms/g) in the casein group (P less than 0.0001), but manganese superoxide dismutase activity was unaffected by protein. Supplementation with methionine increased 54Mn retention from both soy and casein diets (P less than 0.06); activity of manganese superoxide dismutase increased (P less than 0.05) but liver manganese did not change. The addition of arginine to casein diets had little effect on manganese bioavailability. Phytic acid affected neither manganese absorption nor biologic half-life in two experiments, but it depressed liver manganese in one experiment. These results suggest that neither arginine nor phytic acid was the component in soy protein which made manganese more available from soy protein diets than casein diets.
- Research Organization:
- United States Department of Agriculture, Grand Forks, ND (USA)
- OSTI ID:
- 6401138
- Journal Information:
- Proc. Soc. Exp. Biol. Med.; (United States), Vol. 190:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
MANGANESE
METABOLISM
PROTEINS
BIOLOGICAL EFFECTS
SUPEROXIDE DISMUTASE
ENZYME ACTIVITY
ARGININE
BIOLOGICAL AVAILABILITY
BIOLOGICAL HALF-LIFE
CASEIN
LIVER
MANGANESE 54
METHIONINE
PHYTIC ACID
RATS
TRACER TECHNIQUES
WHOLE-BODY COUNTING
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACIDS
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
ENZYMES
ESTERS
GLANDS
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
LIPOTROPIC FACTORS
MAMMALS
MANGANESE ISOTOPES
METALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
OXIDOREDUCTASES
PHOSPHORIC ACID ESTERS
RADIOISOTOPES
RODENTS
TRANSITION ELEMENTS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology
550501 - Metabolism- Tracer Techniques