First hormone isolated from the parathyroid gland to have
hypercalcemic action. PTH is a drug target for hypoparathyroidism and osteoporosis. The presence of PTH in the parathyroid gland was
reported in 1925. It was isolated in 1970 from bovine
parathyroid glands. It was believed that PTH was absent
in fish because the parathyroid gland is thought to appear
when ancestral amphibians evolved. However, PTH was
first identified from the fugu genome database in 2003, and thereafter the existence of PTH has been established
in fish.
