Thyroid iodine metabolism following partial thyroidectomy in the rat.

Abstract

Compensatory thyroid hypertrophy, and thyroid iodine metabolism havebeen studied following hemi- and three-quarter thyroidectomy in the rat. Animals have been studied at different time intervals and at two environmental temperatures, 21° and 26° C. The increase in thyroid remnant weight which follows partial thyroidectomy is accompanied by an increase in iodide-trapping ability (thyroid/scrum ratio), and a more rapid turnover of iodine in the thyroid gland. These changes appear to be a good measure of activation of the thyroid remnant after partial thyroidectomy. DURING the course of a study of hypothalamic influences on the pituitary-thyroid axis it became necessary to standardize techniques in the rat for the measurement of the pituitary thyrotrophic hormone (TSH) response to lowered blood thyroid hormone levels. The classical method for studying this response is the demonstration of regeneration of the thyroid gland after partial thyroidectomy. In the following experiments, this method has been further...