Demonstration of a Hypocalcemic Factor (Calcitonin) in Commercial Parathyroid Extract

Abstract

Intravenous injection of commercial parathyroid extract into fasted dogs resulted in a transient hypocalcemia. The plasma calcium fell 0.40 to 0.65 mg/100 ml within 20 minutes and then rose in the characteristic response to the parathyroid hormone. The hypocalcemic response was similar to that ascribed to the recently reported hormone "calcitonin," and the data suggest that the extract may contain both.