Calcium: Some aspects of subcellular accumulation and distribution in milk
Distribution and bioavailability of {sup 47}calcium in milk labeled by extrinsic and intrinsic methods was investigated. Milk from Sprague Dawley rats was labeled by both methods, and milk from a cow was labeled by the extrinsic method. Retention of {sup 47}Ca from milks administered to young male Sprague Dawley rats was determined through whole body counting for 6 days after administration of milk. Percent of {sup 47}Ca dose retained was 72% for extrinsically labeled cow milk, 62% for extrinsically labeled rat milk, and 55% for intrinsically labeled rat milk. Samples were fractionated by ultracentrifugation and by gel exclusion chromatography. {sup 47}Calcium distributions in rat milk labeled intrinsically or extrinsically were similar. The majority of {sup 47}Ca was found in a particulate, >30,000 molecular weight fraction. The amount of milk calcium retained by rats appeared to be related to the amount of noncasein micelle-associated calcium. When administered by intraperitoneal injection into rats, {sup 45}Ca specific activity of milk peaked in 60 to 90 minutes. In vitro {sup 45}Ca accumulation was compared in Golgi apparatus and endoplasmic reticulum from liver and mammary gland of lactating Dunkin Hartley guinea pigs. In the presence of ATP, highest accumulation per unit total fraction protein was found in Golgi apparatus (mammary gland 28% of available {sup 45}Ca, liver 11%) while 8% was accumulated by endoplasmic reticulum fractions.
- Research Organization:
- Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (USA)
- OSTI ID:
- 5642560
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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CALCIUM
SUBCELLULAR DISTRIBUTION
MILK
CHEMICAL COMPOSITION
ATP
BIOLOGICAL ACCUMULATION
BIOLOGICAL AVAILABILITY
CALCIUM 47
CATTLE
CHROMATOGRAPHY
ENDOPLASMIC RETICULUM
GUINEA PIGS
LACTATION
LIVER
MAMMARY GLANDS
RATS
TRACER TECHNIQUES
ULTRACENTRIFUGATION
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METALS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BODY
BODY FLUIDS
CALCIUM ISOTOPES
CELL CONSTITUENTS
CENTRIFUGATION
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DISTRIBUTION
DOMESTIC ANIMALS
ELEMENTS
EVEN-ODD NUCLEI
FOOD
GLANDS
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MATERIALS
METALS
NUCLEI
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
RADIOISOTOPES
RODENTS
RUMINANTS
SEPARATION PROCESSES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques