Greer M A, Panton P
Am J Pathol. 1973 Dec;73(3):775-88.
Thyroids of rats fed an iodine-deficient diet for several months contain small psammoma bodies within the follicular lumens which concentrate radioactive iodine. If the iodine-deficient rats are fed a high-iodine diet to produce a "colloid goiter" with reaccumulation of PAS-positive colloid around the psammoma bodies before administering radioactive iodine, the radioactivity is present in follicular cells, around the psammoma bodies and in the colloid 24 hours after radioactive iodine administration. Propylthiouracil (PTU) causes radioactivity to disappear from the cells and colloid but does not produce any appreciable discharge of radioactivity from the psammoma bodies. If radioactive iodine is given to the iodine-deficient rats before feeding a high-iodine diet, radioactivity is initially present chiefly in the cells and psammoma bodies and gradually accumulates in the PAS-positive colloid as this becomes deposited under the influence of the increased dietary iodine. If such rats are fed PTU for 4 days before the high-iodine diet is instituted, radioactivity remains limited almost entirely to the psammoma bodies and does not appear in the accumulating colloid. It is concluded that the psammoma bodies are iodinated directly, rather than forming a nidus for condensation of intrafollicular thyroglobulin after it is iodinated. Although iodine is readily bound to the psammoma bodies, it apparently is not easily removed from these structures under in vivo conditions.
连续几个月喂食缺碘饮食的大鼠甲状腺，其滤泡腔内含有小的砂粒体，这些砂粒体可浓聚放射性碘。如果给缺碘大鼠喂食高碘饮食以产生“胶性甲状腺肿”，在给予放射性碘之前，砂粒体周围会重新积聚PAS阳性胶体，在给予放射性碘24小时后，放射性存在于滤泡细胞、砂粒体周围以及胶体中。丙硫氧嘧啶（PTU）会使细胞和胶体中的放射性消失，但不会使砂粒体有明显的放射性释放。如果在喂食高碘饮食之前给缺碘大鼠给予放射性碘，放射性最初主要存在于细胞和砂粒体中，并随着饮食碘增加的影响下PAS阳性胶体的沉积而逐渐积聚在其中。如果在开始高碘饮食前4天给这些大鼠喂食PTU，放射性几乎完全局限于砂粒体，而不会出现在正在积聚的胶体中。结论是砂粒体直接被碘化，而不是在滤泡内甲状腺球蛋白碘化后形成凝聚的核心。虽然碘很容易与砂粒体结合，但在体内条件下显然不容易从这些结构中去除。
