Calcium Metabolism and 47Calcium Kinetics before and after Long-Term Thyrocalcitonin Treatment in Senile Osteoporosis

1. Four women suffering from senile osteoporosis have been treated for 55–60 days with 25 MRC Units per day of porcine thyrocalcitonin with the following metabolic results: (a) slight diminution of plasma, urinary and endogenous faecal calcium levels; (b) slight diminution of plasma phosphate level and urinary phosphate clearance; (c) lowering of serum alkaline phosphatase values; (d) diminution of urinary hydroxyproline excretion; (e) modification of calcium balance toward positive, due to decreased urinary and faecal calcium and to an improvement in intestinal absorption. 2. 47Calcium kinetic studies demonstrated: (a) a slower decline in the specific activity curve after thyrocalcitonin treatment; (b) a slower decline in bone uptake values; (c) a decrease of ‘calcium miscible pool’, ‘calcium turnover rate’, ‘accretion rate’ and ‘resorption rate’ calculated by the method of Aubert & Milhaud (1960). 3. Differences in radiological bone patterns were not observed despite an improvement in the pain after treatment.