Secondary hyperparathyroidism classically appears during the course of chronic renal
failure and sometimes after renal transplantation. Understanding the mechanisms by which
parathyroid hormone (PTH) synthesis and secretion are normally regulated is important in
devising methods to regulate overactivity and hyperplasia of the parathyroid gland after the
onset of renal insufficiency. Rapid regulation of PTH secretion in response to variations in
serum calcium is mediated by G-protein coupled, calcium-sensing receptors on parathyroid …