A Human Parathyroid Carcinoma that Produces Parathyroid Hormone: Long Term Maintenance in Tissue Culture*

Parathyroid carcinoma cells from a pulmonary metastasis of a patient with a serumCa of 17 mg/dl and an immunoreactive parathyroid hormone (PTH) of 6.4 ng eq bovine (b)PTH/ml (normal 40−400 pg/ml) have been maintained in tissue culture for more than2½ years. The cells secrete PTH into the culture media that 1) during immunoassay dilutes in parallel to human hyperparathyroid serum, 2) has a molecular weight similar to intact highly purified bPTH, and 3) stimulates bone resorption in a manner that is equivalent and additive tosynthetic bPTH−(l−34).