The Influence of Age and Sex on the Activity Ratio of Yttrium-90 to Strontium-90 in the Rat Skeleton After Incorporation of Strontium-90

Abstract

The influence of age and sex on the behaviour and distribution of 9% and was investigated in albino rats after administration of solutions with eoSr-gOY in radioactive equilibrium. The ratio of Y/Sr, Q, was found to be proportional to age and was also significantly higher for female animals as compared to males. Sex and age acted additively, increasing the radioactive burden of the bones in the case of female animals substantially.

Endocrine Influences on the Activity Ratio of90Y TO90Sr in the Rat Skeleton After Incorporation of90Sr

“…Parathyroid hormone is also known to cause an increase in the level of free citrate ions Days port protein, the reversibility of which depends critically on pH values (ROSOFF et coll. 1958, STEVENSON 1975. The ion is then free to get incorporated at an available suitable site.…”

“…90Sr in equilibrium with was administered, 5 pCi per rat, intravenously in a single dose. The method employed for radio-assay and calculation of the activity ratio of to 90Sr (Q) has been described in detail previously (STEVENSON 1975 a). Carrier-free in the form of its chloride dissolved in 1 n HCI solution was diluted in physiologic saline for injection.…”

Haematological studies on90Sr-90Y-toxicity: II. Femoral CFU-s kinetics and mitogen response of spleen cells

“…Dilution of 9°Sr-9°Y was made with physiological saline at pH = 7, being optimal for yttrium transport (Stevenson 1975b). A set of previously contaminated glassware and syringes were reserved for the dilution and injection of 9°Sr-9°Y in order to ensure that the injected radionuclides remained in radioactive equilibrium.…”

“…During secondary deposition, the activity-ratio of 90y: 90Sr exceeds one (the value at equilibrium). Activity-ratios of more than one have been measured in femora during the first week post-incorporation, the peak being about day 4 (Stevenson 1975a). During this period, the radiation burden to the marrow is most intensive.…”

Haematological studies on90Sr-90Y-toxicity

“…Physiological saline adjusted to pH 7 as being optimal for yttrium transport (Stevenson, 1975) was used for dilution of the radionuclides. Physiological saline adjusted to pH 7 as being optimal for yttrium transport (Stevenson, 1975) was used for dilution of the radionuclides.…”