抄録
Using the intact male and female adult rats of the Wistar strain, effect ofthyrotropin upon the uptake of I131 by he thyroid gland was investigated with special reference to the morphological changes of the thyroid in parallel to timeresponse. The uptake reached its maximum at the end of 4 hours after injection of thyrotropin, and then decreased with the lapse of time, returning to the normal value after 24 hours.Secretory function was indicated being most activated at 4 hours from morphological point of view.At 18 to 24 hours, the follicular cells were shown evidently swollen and proliferated, but secretory granules, secretory vacuoles and peripheral vacuoles were almost disappeared indicating secretory inactive phase of the glandular elements.Secretory process was cytologically discussed in some detail.
