Low-iodine diet for producing iodine deficiency in rats.
A low-iodine diet has been prepared for rats, using locally available low-iodine ingredients. On analysis it has been shown to consistently contain 15-20 ng iodine/g. When fed to growing female rats, this diet produced severe iodine deficiency while not significantly affecting growth or reproduction. The deficiency was manifested by a fall in daily urinary iodine excretion (to less than 1 microgram/day) and a seven-fold increase in thyroid uptake (131I) observable within 3 months. Levels of plasma thyroxine (T4) and thyroid stimulating hormone (TSH) continued to change for 4-5 months, T4 falling from 69.9 to 7.5 nmol/l and TSH increasing seven-fold from a control value of 364 to 2406 ng/ml. Goitre was present in all iodine-deficient rats and iodine content in the thyroid was 10% of the control value.
D000821:Animal Feed / Q000009:adverse effects*; D000818:Animals; D005260:Female; D005526:Food, Formulated / Q000009:adverse effects*; D006042:Goiter / Q000209:etiology; D006128:Growth; D007455:Iodine / Q000008:administration & dosage / Q000172:deficiency* / Q000652:urine; D011247:Pregnancy; D051381:Rats; D013961:Thyroid Gland / Q000032:analysis / Q000187:drug effects; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
D013972:Thyrotropin; D007455:Iodine; D013974:Thyroxine