The morphologic and physiologic behaviour of thyroid lobes from newborn rats during short periods of incubation in vitro.
Under light and electron microscopic examination, the morphology of thyroid lobes obtained from newborn rats remained essentially normal during periods of incubation in vitro lasting as long as several hours. In response to the presence of TSH in the incubation medium, follicular cells of the lobes extended long microvilli into the follicular lumen and ingested large droplets of colloid. The ability of the lobes to carry out essential steps in the synthesis and release of thyroid hormone during incubation was demonstrated by radiochromatographic analyses. Stimulation with TSH increased the amount of iodide taken up from the medium by the lobes.
Feeney
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L
Dr. Feeney's present address is Department of Ophthalmology, University of Oregon, Portland, Oregon.
Wissig
S
S