Abstract
It has long been known that the administration of iodine and iodine-containing compounds raises the serum level of protein-bound iodine (PBI) even long after discontinuing the administration. A number of studies on the effect of some cholecystographic and pyelographic contrast media on the PBI have been done abroad, but resulted in conflicting information. Moreover, there have been no accurate reports concerning the effect of iodine-containing compounds on the PBI in Japan. Therefore, it was thought of interest to determine the duration of interfering effect of various iodine-containing compounds on the PBI in this study.
The substances investigated were Urografin (Diatorizoate Sodium, for intravenous pyelography and angiography), Moljodol (for hysterosalpingography), Biloptin and Telepaque (for oral cholecystography).
Subjects employed were 88 euthyroid patients and 6 cases of hyperthyroidism without any hepatocholecystic and renal dysfunction. None had any indication of thyroidal abnormality and there was no history of taking interfering medicinal or chemical agents in euthyroid subjects. The PBI was measured before and after administration of a contrast medium. The follow-up studies were performed at varying intervals after administration.
In all 15 euthyroid patients who underwent intravenous pyelography with 20 ml of 76% Urografin (I : 7.4 gm) and 4 patients who underwent angiography with 30 ml of 76% Urografin (I : 11.1 gm), the serum level of PBI recovered to the normal range 2 days after administration, respectively. In 41 sterile but euthyroid women with no obstruction in the tubular pathways, the hysterosalpingography with 10-20 ml of 40% Moljodol (I : 5.32-10.64 gm) inhibited the PBI for approximately one year and a half, although the series as a whole exhibited major variations. In 17 patients given 6 tablets (3.0 gm) of Telepaque (for oral cholecystography, I : 1.98 gm) in a single dose, the PBI recovered within normal range 2 months after administration, while in 11 cases with 6 tablets (3.0 gm) of Biloptin (for oral cholecystography, I : 1.86 gm), the PBI recovered 3 months after administration.
In 6 cases of hyperthyroid patients who had taken 6 tablets of Telepaque in a single dose for oral cholecystography, PBI recovered to the preadministration level about 1-2 weeks after administration. These hyperthyroid patients had been treated with anti-thyroid drugs for a few weeks, but the result of thyroid function tests, such as serum thyroxine level, 131-I triiodothyronine resin sponge uptake and BMR were within thyrotoxic range.
It was concluded that the duration of interfering effect of various iodine-containing compounds on the PBI were defined depending on the sort of, way of administration of, and the content of iodine in the compound and the absorbtion of iodine-containing compound by oral administration, and, that the duration of the interference was shorter in hyperthroid patients than in euthyroid subjects. Moreover, the duration of interference on PBI in euthyroid subjects were shorter than that on 131-I uptake in the case of Urografin (for intravenous pyelography and angiography) administration, about the same as in the case of Moljodol (hysterosalpingography) administration, but longer in cases of Biloptin and Telepaque (for oral cholecystography).
