Use this URL to cite or link to this record in EThOS:
Title: The effect of calcium on thyroid function
Author: Krowinski, Halina Elizabeth
ISNI:       0000 0001 3602 6120
Awarding Body: University of Glasgow
Current Institution: University of Glasgow
Date of Award: 1979
Availability of Full Text:
Access from EThOS:
Access from Institution:
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.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
Keywords: Biochemistry