The calcium-sensing receptor and vitamin D receptor expression in tertiary hyperparathyroidism

Int J Mol Med. 2006 May;17(5):779-83.


The parathormone (PTH) production is controlled by calcium and vitamin D, which interact with the calcium-sensing receptor (CaSR) and vitamin D receptor (VDR), respectively. All of these elements control calcium homeostasis, which is crucial for many physiological processes. Thus, impairment of the upstream component of this system, e.g. a decrease of CaSR and/or VDR, could result in hyperparathyroidism (HPTH). Therefore, the aim of this study was to assess the expression of CaSR and VDR in a tertiary form of HPTH (T-HPTH). The study involved 19 T-HPTH patients qualified for parathyroidectomy and 21 control parathyroids harvested from multi-organ cadaver donors. The small fragments of harvested glands were homogenized and used for Western blot analysis, whereas the remaining tissues underwent routine hematoxylin-eosin staining or immunostaining for CaSR and VDR. Among 64 T-HPTH parathyroids, 58 revealed the morphology of benign hyperplasia, 2 were identified as adenoma and 4 were classified as normal; some glands displayed a mixed histological phenotype. Western blot analysis revealed a decrease of CaSR and VDR in hyperplasia and adenoma-derived samples. However, no correlation between the types of hyperplasia and receptor expression was observed. On the other hand, microscopic analysis of CaSR- and VDR-immunostained sections revealed a highly differentiated and significantly decreased mean expression of both receptors, which correlated with parathyroid histology. The reason behind the impaired expression of CaSR and VDR in T-HPTH is unclear. It presumably results from constant parathyroid stimulation at the stage of S-HPTH, followed by further development of polyclonal autonomy. However, the verification of this thesis requires further study.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blotting, Western
  • Female
  • Humans
  • Hyperparathyroidism / metabolism
  • Hyperparathyroidism / pathology*
  • Immunohistochemistry
  • Male
  • Middle Aged
  • Parathyroid Glands / chemistry
  • Parathyroid Glands / pathology
  • Receptors, Calcitriol / analysis
  • Receptors, Calcitriol / biosynthesis*
  • Receptors, Calcium-Sensing / analysis
  • Receptors, Calcium-Sensing / biosynthesis*


  • Receptors, Calcitriol
  • Receptors, Calcium-Sensing