[Changed body composition by increased total body fat content in experimentally hypothyroid rats].

Total body fat content was determined in growing normal male Wistar rats and hypothyroidized animals 7 weeks after feeding with Methimazol (group MMI-HT), Methyl-thiouracil (group MTU-HT), and performance of radiothyroidectomy by 131-iodine (group R-HT), respectively. At the end of experiments there was an extreme hypothyroid state in all treated groups, verified by external signs, growth kinetics, serum cholesterol estimation and evaluation of the iodothyrosine pattern of the thyroid glands. Changed body composition resulted in all HT-groups from significant increase of total body fat content. The relation of constituents fat : protein : water of 1 : 2 : 6 in the KT-group was changed into 1 : 1 : 3 in the HT-groups. No differences were found between the different HT-groups. Our findings are in good agreement with altered metabolism of plasma lipids described by other authors showing the existence of a highly disturbed lipid metabolism in thyroid hormone deficiency.