Alteration in density, morphology and parathyroid hormone release of dispersed parathyroid cells from patients with hyperparathyroidism.

Dispersed parathyroid cells from normal human and bovine glands and from 10 patients with primary (7 adenomas, 3 hyperplasias) and 4 patients with uraemic hyperparathyroidism (HPT) have been investigated with respect to density, morphology and parathyroid hormone (PTH) release. Percoll density gradients enabled an efficient isolation of viable parathyroid cells which generally banded between 1.035-1.090 g/ml. The average density was significantly higher in cells from the normal than the abnormal glands. The pathological glands contained large chief cells, oxyphil and transitional oxyphil cells and, in one case, water-clear cells which were enriched in fractions with densities below 1.055 g/ml. Measurements of cell diameters revealed an increased proportion of enlarged cells in the preparation of abnormal glands. Nuclear diameters were similar in the normal human glands, adenomas and hyperplasias, but the variability was greater among the adenomas. In comparison to normal bovine parathyroid cells, PTH release of cells from the pathological human glands was reduced and abnormally insensitive to extracellular calcium. The oxyphil and water-clear cells secreted similar amounts of PTH as the chief cells of the abnormal glands. The disturbed PTH release in secondary HPT seemed to be confined mainly to cells within nodules of the hyperplastic glands. The results show that the disturbed hormone regulation in HPT is related to morphological changes of the cells and that buoyant density gradients can be used to accumulate the abnormal cells.