24
Radiod{ological Effects
In the 1940s, there was already much information ahout the effects of high
doses of radiofodine.
Radtolodine was used therapeutically fn the treatment of
Graves' disease to reduce the amount of thyroid hormone produced by the hyper:
active thyroid (Hertz and Roberts, 1942b, 1946; Chapman and Evans, 1946; Soly
and Miller, 1948; Moe et al., 1950; Chapman et al., 1948b) and fn the treatment
‘of thyroid carcinana (Seidlin et al., 1946; Keston et al., 1942; Frantz et al.,
1944; Seidlin et al., 1949; Rawson et al., 1949; Trunnel et al., 1949; Dobyns
and Maloof, 1951).
Radfofod{ne was also used in the treatment of angina pec-
tor{s and congestive heart failure in patients who had normal thyroid function
(Blumgart et a)., 1948; Freedberg et al., 1950); the resultant hypothygoidtsm
decreased cardiac function.
“With the exception of the patients mentioned above who were treated for
heart disease, most exposures of normal thyroid tissue to radfolodine were made
in experimental animals.
High doses were required to Interfere with normal
thyroid functions; therefore, the thyrofd was considered to be fairly radioresistant (Warren, 1943}.
Exposures to suffictently high doses of radinindine
impair the hormogenic capability of the thyroid, and can result in effects that
are statlar to those seen after thyroidectony or as a result of thyroid disease
tnvolving loss of thyrotd function.
Hypothyroid Individuals often manifest a
number of conditions, including dry, cold, and cogrse skin, coarse hair, a
decrease in sweating, weakness, Jethargy, constipation, weight gain, edeua, and,
in the very young, reterded growth.
The effects of damaginy doses of ratio-
todine were studied in a number of animal species, including chiciens (Shanse,
1948; Winchester, 1949), rabbits ent dogs (Hamilton, 1942; Hamilton av
Lawrence, 1942), mice (Sortmen, 1947, 1959, Speert et al., 19533, ant rats