抄録
The metabolism of thyroxine was studied using I131-labeled 1-thyroxine on hyperthyroidism before and after treatment with antithyroid drugs or radioiodine. Thus, the relation between Daily Volume Turnover (DVT) and PBI was observed. The experimental and analytical methods used in this study were essentially the same as that described in Part I.
1) In subjects having clinically attained euthyroid state showing normal BMR after treatment with antithyroid drugs, PBI and DVT values were normal and the DVT value was found to be proportional to the PBI value.
2) In those having clinically attained euthyroid state showing normal BMR after treatment with radioiodine, the DVT value was normal and it was nearly proportional to the PBI value. These could be segregated thereby into two groups : One group showed normal PBI value (A group), and another group showed low PBI value (B group). In the case of B group, after several months duration without any treatment, PBI value turned to normal and B group became normal similar to A group.
3) Subjects retaining hyperthyroid state and showing high BMR in the course of the treatment with radioiodine were segregated into two groups : One group (C group) showed normal PBI but high DVT value, another group (D group) showed high PBI and normal DVT value, though both groups became normal similar to the A group after the success of the treatment.
Thus, we found that DVT value was proportional to PBI in subjects after the success of the treatment of hyperthyroidism, too. From the above, it was found that the evaluation of the effect of the treatment in hyperthyroidism could not be obtained by means of PBI value only. For this purpose, it seemed better to estimate the DVT value after intravenous administration of radiothyroxine and to investigate the relation between DVT and PBI values.
