Metabolism of Sr90 in Adult Beagle Dogs.

Summary 1. Retention and plasma concentration of Sr90 in young adult beagle dogs have been determined for 2 years following a single intravenous injection. Retention (% dose) follows the power function (t in days) R = 70.9 t-0.198. 2. Comparison of these results with those from similar studies with Ra226 shows the anticipated similarity in metabolism of Sr90 and Ra226. However, there are real differences. Sr90 retention is less than that of Ra226 even though Ra226 is excreted more efficiently. This results from higher Sr90 plasma concentration. 3. Since Sr90 deposits mainly in the skeleton and its daughter Y90 does not translocate, this retention equation can be used to calculate average skeletal dose rates for these dogs.