Figure 8.
De novo T3 formation in TG secreted from primary culture of human thyrocytes. Human thyrocytes were grown at two different TSH concentrations: 100 or 1000 milliunits/ml, as described under “Experimental procedures.” A, TG secreted into serum-free media that was not iodinated in vitro served as a negative control; analyzed by SDS-PAGE (2 μg of protein/lane), electrotransfer, and immunoblotting with mAb anti-T3 and anti-TG, as indicated. B, TG secreted from human thyrocytes grown as in panel A was iodinated in vitro and analyzed as in panel A.