The effect of calcium on thyroid function

Krowinski, Halina Elizabeth (1979) The effect of calcium on thyroid function. PhD thesis, University of Glasgow.

Abstract

This thesis investigates the role of calcium in the production of goitre in the rat. In the initial dietary experiments excess calcium carbonate was added to a standard Remington low iodine diet which contains 1% calcitm carbonate. No goitrogenic effect of excess calcium was found. However, when calcium carbonate was added in differing concentrations to a calcium deficient low iodine diet, the thyroid weight increased with increasing dietary calcium. The total calcium content of these thyroids increased and the total iodine content decreased. The serum thyroid-stimulating hormone increased with added calcium although the serum thyroxine did not show any significant change. In other experiments rats were made increasingly iodine deficient before starting the calcium diets. Iodine deficiency appeared to decrease the goitrogenic effect of calcium. In rats made goitrous by administration of propylthiouracil or potassium perchlorate, the addition of 1% calcium carbonate diminished the goitre size. In vivo and in vitro experiments show that the thyroid is capable of accumulating radioactive calcium. In vivo the thyroid uptake of [45]Ca was increased by feeding a low iodine diet. The mechanism of the action of calcium in goitrogenesis is a complex interaction mediated via TSH. Calcium does not affect the trapping of iodide by the thyroid but to a small extent it Inhibits protein binding of iodide. No binding of calcium to thyroglobulin could be detected in vitro. Calcium did not increase the urinary secretion of iodine. The role of calcium in the iodine metabolism of the thyroid is discussed but the precise mechanism of the goitrogenic action of calcium is still not clear.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Endocrinology.
• Colleges/Schools: College of Medical Veterinary and Life Sciences
• Supervisor's Name: Thomson, Dr. J.A.
• Date of Award: 1979
• Depositing User: Enlighten Team
• Unique ID: glathesis:1979-72052
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 17 May 2019 13:13
• Last Modified: 26 Oct 2021 14:36
• Thesis DOI: 10.5525/gla.thesis.72052
• URI: https://theses.gla.ac.uk/id/eprint/72052