Parathyroid chief cells (also called parathyroid principal cells or simply parathyroid cells) are cells in the parathyroid glands which produce parathyroid hormone.
The end result of increased secretion by the chief cells of a parathyroid gland is an increase in the serum level of Calcium. Parathyroid chief cells constitute one of the few cell types of the body that regulate intracellular calcium levels as a consequence of extracellular (or serum) changes in calcium concentration.
The calcium-sensing receptor (CaSR) is sensitive to an increase in serum calcium, and stimulates the uptake of calcium by the parathyroid chief cell. This mechanism is critically important, as it describes a physiological feed-back loop by which parathyroid hormone secretion is down-regulated in response to a restoration of serum calcium.
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