Parenteral magnesium load testing with /sup 28/Mg in weanling and young adult rats
A sound diagnostic test for Mg deficiency is needed. This is a report of the parenteral Mg load test conducted in weanling and young adult rats fed a purified basal diet containing 3 mg magnesium/100 g with 150 mg of added magnesium/100 g (control) or 0 added magnesium (deficient). Weanlings were studied at about 1 week of dietary treatment and young adults at 2 weeks. The protocol included: a) a 6-hour preload urinary collection; b) an intraperitoneal load of 15 mg of magnesium/kg (weanlings) or 12 mg/kg (young adults) with 2 microCi 28Mg given simultaneously with each load; c) a 6-hour postload urinary collection; d) chemical analysis of selected tissues and urine for Mg; and e) 28Mg counting 6 and 24 hours postload. Controls all excreted large amounts of Mg pre- and postload, retaining less than 26% of nonradioactive loads. They had high urinary 28Mg counts. In Mg-deficient animals, the concentration of Mg in bone more than halved. These animals avidly conserved Mg and retained over 85% of nonradioactive Mg loads. Their 28Mg activity in vital organs was 3--6 times greater than in controls. We concluded that the parenteral Mg load test reliably identifies severe Mg deficiency.
- OSTI ID:
- 5405350
- Journal Information:
- J. Nutr.; (United States), Vol. 111:6
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
MAGNESIUM 28
ISOTOPE APPLICATIONS
NUTRITIONAL DEFICIENCY
DIAGNOSIS
AGE DEPENDENCE
COMPARATIVE EVALUATIONS
DIET
NUTRITION
RATS
TIME DEPENDENCE
ALKALINE EARTH ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
EVEN-EVEN NUCLEI
HOURS LIVING RADIOISOTOPES
ISOTOPES
LIGHT NUCLEI
MAGNESIUM ISOTOPES
MAMMALS
NUCLEI
RADIOISOTOPES
RODENTS
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics
551001 - Physiological Systems- Tracer Techniques