Study of Parathyroid Glands in Patients Suffering from Secondary Hyperparathyroidism due to Chronic Renal Failure: Relationship between the Density of 1,25-Dihydroxyvitamin D_3 Receptor and Proliferative Activities

To clarify the relationship between the 1,25-dihydroxyvitamin D_3 receptor (VDR) density and proliferative activities of parathyroid cells, 18 parathyroid glands surgically removed from patients suffering from secondary hyperparathyroidism due to chronic renal failure were examined histologically and immunohistochemically with anti-VDR antibody and antiproliferating cell nuclear antigen (PCNA) antibody. This revealed a significantly lower positive VDR staining ratio in nodular hyperplasia (nodular type) of the parathyroids than in diffuse hyperplasia (diffuse type). The number of positive PCNA staining cells in nodular type was significantly greater than in diffuse type. A negative correlation was found between VDR density and PCNA expression. These results indicated that the decrease in VDR density was associated with the proliferative activity of the parathyroid cells in secondary hyperparathyroidism