[Modification of maximal binding capacity and radio-T3/T4 distribution by carbamazepine and diclofenac]. / Beeinflussung der maximalen Bindungskapazität und der Radio-T3/T4-Verteilungen durch Carbamazepin und Diclofenac.

Marked changes in plasma thyroid function parameters due to medication have been described in literature. We, therefore, studied the influence of routine administration of carbamazepine and diclofenac upon the radio T3/T4 distribution to specific thyroid transport proteins as well as their maximal binding capacity (MBC) for T4. Both drugs have been found to lead to changes in T3 and T4 distribution but not to any influence upon MBC. The parameters of thyroid function mostly revealed reduced FT3 and FT4 values while bTSH was affected only by carbamazepine administration.

[Beta-carotene, vitamin A and carrier proteins in thyroid diseases]. / Beta-Carotin, Vitamin A und seine Trägerproteine bei Schilddrüsenerkrankungen.

The conversion of beta-carotene (provitamin A) to 2 molecules of vitamin A (retinol) is accelerated by thyroxine and hyperthyroidism, respectively. The characteristic yellow tint of the skin in hypothyroidism is due to hyper-beta-carotenemia. Both in hyper- and hypothyroidism in a retinol deficiency has been observed in literature. In a series of 36 patients (16 hyper-, 8 hypo-, and 12 euthyroid) serum samples were analyzed for retinol and beta-carotene levels (high pressure liquid chromatography) as well as retinol binding protein (radial immune diffusion), prealbumin (nephelometry), and serum zinc values (atomic absorption spectrometry) were established. The beta-carotene serum level in the hypothyroid group (mean 1.1 microgram/ml) was significantly higher (p < 0.05) in relation to euthyroid controls (0.6 microgram/ml), the hyperthyroid group showed significantly lower values (0.3 microgram/ml). RBP and prealbumin concentrations were significantly lower (p < 0.05) in hyperthyroid as against eu- and hypothyroid patients. Surprisingly, in all 3 groups the retinol levels were not significantly different, although the hyperthyroid group was slightly lower (0.6 microgram/ml) than the mean value of 0.7 micrograms/ml in the other groups. A vitamin A and protein rich food, customary in Central Europe, seems to rule out any vitamin A deficiency both in hyper- and hypothyroidism. However, the beta-carotene values are significantly higher in hypothyroidism, while in hyperthyroidism they were lower. As intrahepatic zinc content plays an important role in the synthesis of RBP and its secretion together with retinol, we also analyzed this component: The serum zinc levels in hyperthyroid patients were clearly higher (79.1 micrograms/dl) than in the hypothyroid group with 57 micrograms/dl (p < 0.05).

[Iodine and thyroid hormone metabolism in pregnancy]. / Jod- und Schilddrüsenhormonstoffwechsel in der Schwangerschaft.

The influence of pregnancy on thyroid function as well as important interactions of pregnancy and thyroid disorders are of high clinical importance. During the last decade knowledge of these issues greatly influenced clinical aspects and basic science. Because of the increasing frequency of thyroid disorders during pregnancy, knowledge of these issues is important in order to diagnose, treat and manage all patients exposed to these problems.

[Familial dysalbuminemic hyperthyroxinemia in long-term amiodarone treated patients]. / Familiäres dysalbuminämisches Hyperthyroxinämie-syndrom unter Amiodaron-Langzeitbehandlung.

A serum sample of an outpatient, under long-term amiodarone (AM) treatment was submitted for routine checkup of thyroid function parameters. It revealed the pattern of euthyroid dysalbuminemic hyperthyroxinemia. Since no results have been published so far covering the influence of amiodarone on the specific thyroxine binding proteins, we undertook a prospective study to investigate 28 amiodarone patients, comparing these with a series of age and sex matched euthyroid subjects. Not one amiodarone patient showed changed radio-T4 distribution against the normal group. Yet, in 3 relatives of the propositus, familial screening revealed the typical pattern of thyroid function tests and of T4 distribution in radio immune ice gel electrophoresis, respectively, proving familial dysalbuminemic hyperthyroxinemia syndrome. Thus, it is most likely that this syndrome has been prevalent already prior to the amiodarone administration and consequently amiodarone was of no influence on thyroxine transport protein patterns.