THE METABOLISM OF Sr 90 AND Y 90 AND THE INFLUENCE OF LACTATION ON RETENTION

Technical Report · Fri Oct 31 04:00:00 EST 1958

OSTI ID:4329103

Hoecker, F E; Shaw, E I

Detailed studies of the metabolic history of strontium90 and yttrium-90 in terms of retention as influenced by gestation and lactation are reported for rats which received intraperitoneal injections either 52 days before parturition or within 24 hours after parturition. Retention periods ranging from 7 minutes to 100 days are covered for 11 body compartments including soft tissue, bones (excluding femurs), femurs, blood, mammary glands, kidneys, liver, muscle, testis, spleen,and litters. Data for Sr/sup90/--Y/sup 90/ in equilibrium are based on crystal detection of bremnsstrahlung in which energy dependence errors are elimated by spectrometric analysis and geometrical errors arc avoided by digesting or homogenizing tissues, Y/sup 90/ and Sr/sup 90/ are studied separately by half-life measurements based on betaparticle detection. When compared with unbred controls the retention of Sr/sup 90/ in the bones -of rats injected 52 days prepartum is not significantly influented by lactation, but that of animals injected at parturition is markedly affected. When the % of dose retained by the latter group is plotted versus time after injection, the depletion of calcium in the bones during gestation is reflected by increased Sr/ sup 90/ uptake for the first 5 hours after injection at which time the uptake in both the controls and in the postpurtum group reaches a maximum of 42 percent. From this value the retention in both decreases with time although lactation in the postpartum group is responsible for a much greater rate of elimination of Sr/ sup 90/ during the first 18 days of lactation which results in a retention of only 5% of the dose at 100 days as compared with a retention of approximately 15% in the controls at that time. Data on soft tissue retention show approximnately 80% in all groups at7 minutes after injection. Greater avidity of the bones is again shown by a slightly lower soft tissue retention in the postpartum group although this lower retention vanishes at 7 hours after injection, after which time the soft tissue content increases from 25% to reach a maximum of 37% in 24 hours. This increase in soft tissue retention coincides with the onset of lactation and reflects mobilization of calcium (and hence Sr/sup 90/ from the bones. It also coincides with the time of decreased bone retention referred to above. Sr/sup 90/ concentration in the blood decreases by a factor of 7 during a period of 2 hours following injection. In the control group the blood content is essentially zero within 24 hours, while in the lactating group the Sr/sup 90/ concentration reaches a minimum at 24 hours but undergoes an increase which coincides with the increase in soft tissue content resulting from the onset of lactation. (auth)

• Research Organization: Kansas. Univ., Lawrence
• NSA Number: NSA-12-014602
• OSTI ID: 4329103
• Report Number(s): A/CONF.15/P/1996
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AGE-- BLOOD-- BODY-- BONES-- CONFERENCE-- FEMUR-- GLANDS-- GONADS-- INTESTINE-- KIDNEYS-- LIVER-- MAMMARY GLANDS-- METABOLISM-- MUSCLES-- PARTURITION-- PERITONEUM-- PHYSIOLOGY-- PREGNANCY-- RATS-- SEX-- SPLEEN- - STRONTIUM 90-- TESTES-- TISSUES-- YTTRIUM 90
BETA PARTICLES-- BONES-- BREMSSTRAHLUNG-- CRYSTAL COUNTERS-- ENERGY-- ENZYMES-- ERRORS-- GLANDS-- HALF- LIFE-- HOMOGENEOUS REACTORS-- LACTATION-- MAMMARY GLANDS-- MEASURED VALUES-- METABOLISM-- MILK-- PARTURITION-- PREGNANCY-- QUANTITY RATIO-- RADIATION DETECTORS-- RATS-- SPECTROMETERS-- STRONTIUM 90-- TISSUES-- VARIATIONS-- YTTRIUM 90
BIOLOGY AND MEDICINE
BLOOD-- BONES-- CALCIUM-- GLANDS-- LACTATION-- MAMMA