Radiopharmacological profiles of tracers under pathophysiological conditions. 99mTc-methylene diphosphonate uptake by...

The uptake of 99mTc-MDP, a skeletal radiotracer, was studied at early and late (3 h) time intervals in rats induced with altered thyroid status. Thyroid dysfunction resulted in disturbances in bone mineral metabolism. Rats rendered hypothyroid showed an overall retardation in growth and also considerably reduced skeletal uptake, especially at early time periods. On the other hand, rats rendered hyperthyroid did not show any significant alteration of the skeletal uptake as compared with controls despite enhanced bone turnover normally observed in hyperthyroidism.