IN VITRO UPTAKE OF 131I LABELLED L-TRIIODOTHYRONINE BY HUMAN ERYTHROCYTES

Abstract

ABSTRACT The uptake of 131I labelled l-triiodothyronine by erythrocytes was studied in 139 patients in the presence of equal parts of homologous serum. In 54 normal subjects the uptake was found to range from 6 to 10.5 per cent of the added activity, while 3 subjects (5.6 per cent) showed values from 10.5 to 12.2 per cent. Out of 16 hyperthyroid patients 14 (87.5 per cent) had elevated values. There was a distinct relationship between the severity of thyrotoxicosis and the extent of the uptake. Out of 8 hypothyroid patients 4 (50 per cent) had reduced uptake. Among 12 pregnant women uptake was reduced in 10 and among 8 patients on stilboestrol medication it was reduced in 8. Three out of 7 patients with long-standing hepatitis showed reduced erythrocyte uptake. With one exception the uptake was normal in 13 patients with non-toxic goitre, in 8 euthyroid thyroidectomized patients, in 4 euthyroid patients treated with desiccated thyroid, in 6 euthyroid hypermetabolic and in 3 euthyroid hypometabolic patients.