Loss of Organ Specific Characteristics of Hog Thyroid Cells During Growth in vitro . ∗

Abstract

Summary

Normal hog thyroid glands were treated with enzyme and the dispersed cells cultured in vitro. Radioactive iodide (I¹²⁵) was added to the growth medium so that the duration of synthesis of thyroglobulin, MIT, DIT, T₃, and T₄ could be measured. Thyroglobulin production was measured by radio-immunoelectrophoresis and tanned cell hemagglutination inhibition tests. The iodinated amino acids were analyzed by hydrolyzing cell sonicates and separating the iodoamino-acids by thin-layer chromatography. Radioactivity of each amino acid was detected by direct counting in a well scintillation counter and by observation of a radioautograph prepared from a duplicate chromatography plate. Thyroglobulin was synthesized during the first 3 days of in vitro growth. Radioactively labeled T₃ and T₄ were detected during this same time period. The synthesis of MIT and DIT continued for at least 2 additional days. Serum albumin containing I¹²⁵ was detected by radioimmunoelectrophoresis during the first 7 days of growth. Hog kidney cells when tested in an identical manner did not iodinate proteins or amino acids.