[Short-term biological effects of synthetic salmon calcitonin in Paget's disease. Influence of posology]

Abstract

In ten patients with Paget's disease of bone (Group I) intramuscular injection of 50 MRC units of synthetic Salmon calcitonin (SCT) induced a marked decrease of serum calcium (-1,444 mg%), serum phosphorus (-1,06 mg%), urinary total hydroxyproline (-71%), and a marked increase of urinary cyclic AMP (+ 114%). These changes occur at maximum 6 hours after the injection with a return to the initial values after 24 hours. In six other patients with Paget's disease (Group II) the acute biological effects were of the same nature and magnitude after the injection of 100 MRC units of SCT. In this group a significant but temporary increase of the plasma parathyroid hormone level was demonstrated. The magnitude of the hypocalcemia seems proportional to the initial serum alkaline phosphatase and urinary hydroxyproline levels. After one month of treatment, the alkaline phosphatase and urinary hydroxyproline have more marked and more regular decrease in group II who received 100 MRC units of SCT daily than in group I who received 50 MRC units three times a week. The cellular mechanisms of these biological changes are discussed. A posology of two daily injections of 50 MRC units of SCT is suggested when a quick and maximum stoppage of pagetic remodeling is required.