Qualitative Changes in the Secretion of Thyroid Hormones Induced by Iodine Deficiency

Plasma free and total iodothyronine levels in the newborn lamb. Physiological considerations

“…Firstly, plasma total and free T4 and T3 levels were much lower in the second (standardized bottle-fed lambs) than in the first (suckling lambs) experiment ; as we previously observed that plasma active iodothyronine levels were positively related to birthweight in the lamb (Cabello and Levieux, 1981 ;, this difference is not surprising (mean birthweight : 2.29 vs 3.57 kg). Secondly, neonatal changes were not similar in the two experiments ; this could be due to different birthweights in the two groups of lambs, but also to the different nutritional schedules used : in our experimental conditions, colostrum bottle-feeding induced some degree of undernutrition Wrutniak and Cabello, 1986 (Fisher et al, 1977) could induce a preferential thyroidal T3 hypersecretion, as observed during iodine deficiency (Greer et al, 1968). However, in previous work , the peak T3 level was shown to occur before the peak T4 level after TSH administration in the newborn lamb.…”

In Vivo Evaluation of Transdermal Iodide Microemulsion for Treating Iodine Deficiency Using Sprague Dawley Rats

“…All measurements are in millimeters (mm) no change in T 3 during the first few weeks and up to a month of the study (37). While T 4 has shown decreasing values during iodine deficiency, T 3 usually shows contradicting results (36,38). Surprisingly in some studies, T 3 decreases significantly within weeks or months while in other studies T 3 shows no changes in values (39).…”

Endemic Goiter in Sarawak, Borneo Island; Prevalence and Pathogenesis

“…However, Arulambalam in Kuching, the capital of Sarawak, has reported three pathologically documented thyroid cancers in Dayak people (1968). Malignant transformation of endemic goiter has been suggested variously (Miyasaki et al, 1967 Secondly it is known that T3 is predominantly produced when rats are fed on low iodine diet (Greer et al, 1968). DeVisscher et al(1961) showed increased serum T3 in the endemic goiter in Congo.…”