Parathyroid Morphology in Gerbils After Thyroidectomy and Calcium Administration

Abstract

Morphological studies of the parathyroid glands from adult Mongolian gerbils in which hyper‐calcaemia had been induced by thyroidectomy and calcium injections for 2–19 days were carried out. The potassium pyro‐antimonate technique and subsequent X‐ray analysis of the precipitates were used for ultrastructural localization of cations. Ultrastructurally, most (suppressed) chief cells exhibited a dense cytoplasm, medium‐sized or large mitochondria, glycogen particles, inconspicuous endoplasmic reticulum and Golgi complex, calcium‐containing precipitates mainly in mitochondria and nuclei, and sometimes also lysosomal bodies and accumulations of secretory granules which occasionally seemed to be discharged into cytoplasmic vacuoles. A few parenchymal cells showed a low cytoplasmic density, few organelles, and structurally altered mitochondria, occasionally with associated smooth‐surfaced vacuoles. These cells possessed calcium‐containing precipitates in mitochondria, smooth‐surfaced vacuoles, and also diffusely in the cytosol. It is concluded that, in the main part of the parenchymal cells, the hypercalcaemia had resulted in a suppression primarily of the synthetic and later also of the secretory activity, and that the calcium‐containing precipitation is different in the chief cell variants.

The predictive factors for postoperative hypoparathyroidism and its severity on the first postoperative day after papillary thyroid carcinoma surgery

“…According to the literature review, no adequate evidences were found to demonstrate that hypoparathyroidism would benefit from PCS. Oppositely, previous study indicated that the administration of calcium supplementation may inhibit PTH secretion by virtue of a negative feedback mechanism [23]. Therefore, the intervention of calcium supplementation on postoperative day 0 after PTC surgery might inhibit the secretion of PTH secretion, which consequently raising the risk of hypoparathyroidism.…”

Quantitative Parathyroid Morphology Is Unaltered in Prolonged Hypocalcemia

“…The proportional control of parathyroid hormone secretion by the extracellular concentration of calcium has been firmly established both in vivo (Sherwoodet al 1968, Blum et al 1974 Altenuhr 1970,1972, Capen 1971, Oldhamet al 1971, Black et al 1972b, Schoumura 1972, Boquist 1975, Boquist and Fahreaus 1975, Boquist and Lundgren 1975. In these studies divergent opinions have been presented about the ultrastructural characteristics of the supposedly active parathyroid parenchymal cell.…”

Predictable Criteria for Selective, Rather Than Routine, Calcium Supplementation Following Thyroidectomy

“…4 In addition, unnecessary calcium or hypercalcemia may suppress normal parathyroid hormone secretion and may result in prolonged suppression of glands that may be mildly ischemic. 3 Our clinical management aims to keep serum calcium levels in the low-to-normal range to prevent unwanted PTH suppression.…”

“…The routine administration of supplemental calcium and calcitriol can be inconvenient, may lead to unwanted adverse effects such as constipation, and may inhibit PTH production by means of a negative feedback mechanism. 3 In addition, the burden of frequent biochemical assessments (ie, of serum calcium and PTH levels) after discharge from the hospital can be demanding for both the patient and the medical team. The aim of our study was to identify patients at risk for developing symptomatic hypocalcemia after completion or total thyroidectomy, and to create recommendations for safe, selective calcium/calcitriol supplementation.…”