Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.593585
Title: Factors affecting thyroid function in human pregnancy
Author: Tulloch, Marian I.
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 1966
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Abstract:
As in many other fields, advances in the biochemistry and physiology of the thyroid gland have mainly followed the introduction of new techniques for the assessment of thyroid and related functions. One of the major innovations has been the availability of the isotope I131 which was first produced in the cyclotron in 1934. The earliest physiological experiment using I131 was reported in 1938 by Hertz, Roberts and Evans. Early measurements were concerned with the thyroid uptake of radio-iodine from the plasma but it soon became apparent that there was not a simple relationship between the uptake of radio-iodine by the thyroid and its secretion of thyroid hormone. One of the problems encountered was the influence of the renal clearance of iodide on thyroid uptake and the use of thyroidal plasma clearance of radio-iodine as an independent parameter of thyroid function was described by Myant in 1949. By studying the metabolism of an intravenous tracer dose of radio-iodine it is possible to establish the relative distribution of iodide from the plasma into the various iodide pools, but no information on the absolute amounts of iodide involved can be obtained unless the specific activity of the iodide in the plasma is known. The concentration of iodide in the plasma is normally too small to measure directly but an indirect method was described by Stanley in 1949 and has since been extensively utilised in studies of iodine metabolism (Perry and Hughes, 1952; Reilly et al., 1958; Feinberg et al., 1959; Alexander et al., 1962). In more recent years attention has been focused onto the circulating thyroid hormones and their carrier-proteins in the serum. Only the fraction of free or unbound thyroid hormone in the serum diffuses into the tissues but it has not been established whether only free hormone can be effective at the sites of action in the Cell (Tata, 1964). The study of bound and unbound thyroid hormones in the serum has been facilitated by the availability of thyroid hormone labelled with radio-iodine, and by the development of techniques such as zone electrophoresis and equilibrium dialysis. Many bioassays for the measurement of pituitary thyrotrophic hormone (TSH) (McKenzie, 1958; Adams and Purves, 1957) have been developed but few are capable of measuring physiological levels of TSH and thus their use in the study of normal thyroid physiology is limited. With the development of these techniques it has become possible to investigate many aspects of physiology and pathology of the thyroid gland and to throw some light on problems which were hitherto difficult to elucidate. One such problem is the occurrence of maternal thyroid enlargement during human pregnancy. This phenomenon has been known almost throughout historical times but our knowledge of its aetiology and its implications is still incomplete.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.593585  DOI: Not available
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