RESPONSE OF THYROID C-CELL SYSTEM IN RAT TO LONG-TERM HYPERCALCEMIA

  • 1 January 1976
    • journal article
    • research article
    • Vol. 67  (3) , 315-321
Abstract
Long-term hypercalcemia induced in rats by administration of vitamin D3 and CaCl2 for 60 days resulted in strong hyperplasia and hypertrophy of the C-cells. The extent of hyperplasia varied greatly in individual animals. Histochemical reactions, especially the masked metachromasia with toludine blue, demonstrated cell groups in which no reaction was observed in addition to those exhibiting a very strong reaction. Impregnation with Ag according to Cajal showed a diminished number of argyrophilic granules in the C-cells, which had undergone hyperplasia. The reactions for non-specific esterases and cholinesterases were similar both in the experimental animals and in the controls. Enlargement of the C-cell nuclei in the experimental group also was pronounced. The total serum Ca level was only slightly increased in this group. The results of staining and the enlargement in nuclear volume of C-cells reflect the increased activity of these cells. Hyperplasia of the C-cells may represent a type of adaptation of the endocrine system in order to maintain Ca homeostasis.