DNA synthesis and secretory activity in parathyroid adenomas.

DNA synthesis was measured in vitro by incorporation of [3H]thymidine into DNA in 42 parathyroid chief cell adenomas immediately after surgical removal. The results ranged from 18 to 185 DPM/microgram DNA and showed a positive correlation with pre-operative values for serum immunoreactive parathyroid hormone (r = + 0.47; P < 0.001) and plasma calcium (r = + 0.35; P < 0.05). There was no correlation between DNA synthesis and tumour weight or mean diameter of tumour cell nuclei. The results suggest that DNA synthesis and cell division in parathyroid adenomas are determined in part by the secretory activity of the tumour. DNA synthesis measured on one occasion is not necessarily an overall index of tumour growth.