Comparative Metabolism of Radium, Strontium, and Calcium

Norris, William P.; Kisieleski, W.E.

doi:10.1101/sqb.1948.013.01.022

Cited by 44 publications

(7 citation statements)

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“…Blood data for the first 24 hours were not presented in their report (23). Norris and Kisielski, on the other hand, found that the blood concentrations of Sr89 remained above those of Ca45 in mice receiving tracers intravenously (30).…”

Section: Resultsmentioning

confidence: 89%

Strontium and Calcium Metabolism in Metabolic Bone Diseases *

Dow¹,

Stanbury²

1960

J. Clin. Invest.

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Skeletal and systemic disease may be reflected in profound alterations of the metabolism of the bone salts. In human skeletal disease attention has focused, for the most part, on the altered metabolism of calcium. Several studies indicate that strontium may have a metabolic pathway similar to that of calcium and that radiostrontium, because of its ease of measurement, might be a convenient indicator for observing the transfer of calcium through the calcium-containing compartments of the body.The investigations to be reported here are concerned with the comparative distribution and fate of calcium and strontium in subjects with altered bone metabolism. Patients with thyroid and parathyroid disease, osteoporosis, and Paget's disease were studied after simultaneous intravenous administration of strontium85 and calcium45. The results indicate that Sr85 closely parallels Ca45 as an index of skeletal function. MATERIALS AND METHODSAll patients (Table I) were on the Metabolic Research Ward, were ambulatory throughout the study, and spent a few hours out of doors each day with a nurse in attendance. Each received a constant neutral ash diet containing 88 to 206 mg of calcium per day (Table II). The calculated daily magnesium intake did not exceed 200 mg. Fluid intake was kept between 2,000 and 2,500 ml per day. After a minimum of 7 days on the fixed diet, a 3-day control collection of urine and feces was obtained before administration of the labeled isotopes.The dose of labeled calcium and strontium was prepared from hydrochloric acid stock solutions of Ca"C121 of high specific activity, and from carrier-free Sr5'Cl,.

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Section: Resultsmentioning

confidence: 89%

Strontium and Calcium Metabolism in Metabolic Bone Diseases *

Dow¹,

Stanbury²

1960

J. Clin. Invest.

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“…For instance, the injected radiostrontium disappears rapidly from the blood stream (13,15); the ingested tracer can be detected within a few minutes in the plasma, the radioactivity increases gradually, reaches a peak by 2 to 4 hours and declines slowly thereafter.…”

Section: Discussionmentioning

confidence: 99%

“…Some of these results were recently published (1-4). The metabolism and skeletal uptake of radiostrontium were extensively studied in various species of animals: the isotope was fed or administered parenterally to young, adult and pregnant animals (12)(13)(14)(15), the effect of various diets was investi- gated upon the metabolism of radioactive strontium (12,14,15) and the uptake in various parts of the skeleton was studied by radio-assay and autoradiographic techniques (12,16,17). Acute and chronic toxicity of radiostrontium were investigated (18)(19)(20)(21).…”

Section: Discussionmentioning

confidence: 99%

Strontium85 and Calcium45 Metabolism in Man 12

Spencer¹,

László²

1957

J. Clin. Invest.

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Preliminary reports were recently published from this laboratory on the metabolism of intravenously administered radiostrontium and on the effect of calcium upon strontium excretion in man (1, 2). The absorption, the digestive juice excretion and tissue retention have been studied following the oral and intravenous administration of Sr85. Furthermore, the metabolism of orally administered radiostrontium has been compared with that of radiocalcium in the same patients (3,4). These data form the basis of this communication. MATERIALS AND METHODSThe six patients listed in Table I Sr' is a carrier-free isotope5 produced by bombardment of rubidium!. It is a pure 'y-emitter, its energy is 0.51 mev. and its half-life is 65 days. The radioactivity of duplicate samples of plasma, urine and stool was measured in a well-type scintillation counter. The stability of the counting arrangement was checked daily against a uranium standard. The statistical counting error varied: in the initial phases of the experiment sufficient counts were taken to keep the probable error within 2 per cent. In later phases, counting rates were lower, and it was not feasible to maintain this precision, so that counting errors as high as 5 per cent were incurred. Standards were prepared for each patient at the time of administration of the isotope by delivering the same dose into a volumetric flask; appropriate dilutions were then prepared for counting. The standards were counted along with each set of experimental samples, thereby correcting for the decay of the isotope.The radioactivity was determined on 2 to 5 ml. of plasma obtained 5, 15 and 30 minutes and 1, 4, 8 and 24 hours after the ingestion or injection of the isotope. Thereafter, plasma was obtained every morning in the post-absorptive state during the first week of each study and 2 to 3 times per week thereafter. The plasma radioactivity was calculated for the total plasma volume which was determined for each patient using T-1824 dye (6). The urinary output was separated on the day of the isotope administration in fractions at 1, 4, 8 and 24 hours. On the subsequent days, the 24-hour urine output was collected. Aliquots of 2 to 5 ml. of urine were used for radio-assays. Each stool specimen was collected separately, water was added to obtain a homogeneous mixture in a Waring blendor. The weight of the homogenate was determined and aliquots of 4 to 5 gm. were assayed in the scintillation counter. Multiple analyses of such aliquots indicated homogeneous distribution of the isotope. Since the radioactivity of the stool specimens was high after the ingestion of the tracer, these specimens were counted in a bismuth cathode y-counter. The radioactivity was determined on the total stool homogenate and on several water rinses of the Waring blendor using Marinelli beakers.Two patients (2 and 6, Table I) also received an oral tracer of Ca prior to the administration of oral Sr'.

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“…The gamma variate has been suggested as a substitute fitting function for polyexponential series, in various applications, since at least 1948 (1,2). These suggestions have been, generally, for the fitting of monotonic descending data.…”

Section: Introductionmentioning

confidence: 99%

Gamma variate fits to pharmacokinetic data

Pfeffer

1988

European Journal of Drug Metabolism and Pharmacokinetics

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The gamma variate, C = Ataexp(-bt), was tested, as a fitting function, with various real and error-free simulated intravascular and extravascular pharmacokinetic data sets and the results compared with polyexponential fits. For extravascular data, the gamma variate is only suitable to globally fit data which might otherwise be described biexponentially. For intravascular data, the gamma variate could only fit a limited range of the possible concentration-time profiles. Gamma variate fitting algorithms must minimize relative deviations; fits using unweighted sums of squared deviations gave excellent results at higher concentration values but consistently underestimated terminal descending portions of the data.

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Comparative Metabolism of Radium, Strontium, and Calcium

Cited by 44 publications

References 0 publications

Strontium and Calcium Metabolism in Metabolic Bone Diseases *

Strontium and Calcium Metabolism in Metabolic Bone Diseases *

Strontium85 and Calcium45 Metabolism in Man 12

Gamma variate fits to pharmacokinetic data

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