High-dose intravenous thyroxine (T4) is the preferable treatment for myxedema coma. We describe the clinical course of a 69-year-old man who presented with myxedema coma and received oral levothyroxine (LT4) therapy (1 mg) in a split dose. This suggests split high-dose oral LT4 as a therapeutic option in myxedema coma.

The contribution of L-thyroxine (T4) to nuclear thyroid receptor occupancy was studied in GC cells incubated with concentrations of 3,5,3'-triiodo-L-thyronine (T3) and T4 that resulted in free iodothyronine levels similar to those in serum of euthyroid rats. T4 accounted for 5.4-10% of the occupied receptors: T3 derived from T4 [T3(T4)] and T3 added to medium accounted for the remainder of rece...

125I-Labeled N-bromoacetyl derivatives of L-thyroxine and L-triiodothyronine were used as alkylating affinity labels to identify rat liver and kidney microsomal membrane proteins which specifically bind thyroid hormones. Affinity label incorporation was analyzed by ethanol precipitation and individual affinity labeled proteins were identified by autoradiography after separation by sodium dodecy...

Eight children with cystinosis (3 with renal transplants, 2 on maintenance haemodialysis, 2 with chronic renal failure, and one with normal renal function) were studied for evidence of hypothyroidism, and compared with a control group of children with chronic renal failure due to other causes. Abnormal thyroid function was present in all the cystinotic patients: thyroxine (T4) low in 1, free th...

Iodine (I2) has been proposed to be used as a water disinfectant on the manned space station. Previous work has shown that subchronic administration of I2 to Sprague-Dawley rats in drinking water significantly increases plasma thyroxine/triiodothyronine (T4/T3) levels. This is not observed with iodide (I-) treatment. The present study addresses the possibility that I2 reacts with deiodinated T4...

Changes in thyroid hormone concentration and distribution and plasma cortisol levels have been followed in 11 patients undergoing elective cholocystectomy. A significant rise in total and free thyroxine (T4) and fall in total and free triiodothyronine (T3) were noted after surgery. Reverse T3 concentrations rose substantially, suggesting that peripheral conversion of T4 to T3 is diminished and ...

Preclinical studies have attributed 3,3',5-triiodo-L-thyronine (T3) a direct negative effect on tumor progression, as well as chemosensitizing, differentiating and immunomodulatory properties. On the other hand, L-thyroxine (T4), via a thyroid hormone receptor on plasma membrane integrin αvβ3, promotes solid tumor growth and neoangiogenesis, therefore lowering endogenous T4 reduces tumor growth...

Three commerciallyavailablekitsfordetermining serum thyroxine (T4) by column were evaluated. Results with all were less than satisfactory, but a series of changes in the Oxford method resulted in increased reproducibility, substantially improved recovery, and extended linearity of the standard curve. Results compared well with the thyrometabolic status of patients and normal individuals. The 95...

It is a fact of great interest that when 131I-thyroxine and 131I-triiodothyronine are exogenously given, they are highly concentrated in the anterior hypothalamus, median eminence, and hypophysis. Schittenhelm and Eisler (1932) already found that the intravenous injection of 1.0mg/kg of thyroxine (T4) into dogs, cats and rabbits elevated iodine concentration in the tuber cinereum 10times. Since...