The Cycling of Calcium as an Intracellular Messenger
The concentration of calcium in a cell has generally been portrayed as a switch turning cellular processes on and off. But the ion's role in prolonged responses belies the traditional model
Calcitonin
This recently discovered thyroid hormone plays an important role in metabolism: it inhibits the breakdown of bone and thus keeps the calcium in the blood from reaching an excessively high level
The Parathyroid Hormone
A protein hormone that proved difficult to isolate, it acts upon bones, kidneys and gastrointestinal tract to regulate the level of calcium in the internal environment of the body