Determination of 90Sr and stable strontium in bones from sheep ewes and their fetuses

Abstract

The concentrations of 90Sr and stable strontium were measured in the bone ash from pregnant sheep ewes and their fetuses. The fetuses weighed from 125 g ( 90Sr) and 110 g (stable strontium) to 2650 g. In the ewes the average concentration of 90Sr was 40.4 (s.d. 6.4) pc/g calcium in the metatarsal diaphyses and 38.4 (s.d. 3.9) pc/g calcium in the vertebrae. The average concentration of stable strontium was 321 (s.d. 37) p.p.m. in the metatarsal diaphyses and 324 (s.d. 26) p.p.m. in the vertebrae. No significant difference between the two bones in the concentrations of either 90Sr or stable strontium was found. In the fetuses the average concentrations of 90Sr and stable strontium in the ash from the ossified parts of the long bone diaphyses was 16.2 (s.d. 2.5) pc/g calcium and 152 (s.d. 27) p.p.m. respectively. The average ratio between the strontium concentrations in the long bones of each fetus and the metatarsal bones of its mother was 0.41 (s.d. 0.06) for 90Sr and 0.48 (s.d. 0.08) for stable strontium. The strontium concentrations in the fetal and maternal bone ash, and the ratio between these concentrations, were essentially independent of fetal weight and sacrifice date.