- [9 detectable levels, the degree of damage may <hen preclude neoplasmidevelopment.
The
need for a very sensitive TSH assay was obvious in an experimental|design to test the
subtle effects that TSH might have in irradiated animals that should be developing
neoplasms some of which were given supplemental T,:
Some of our observations on the Marshallese patients have prappted us to questior
the part played by TSH in the origin of neoplasms, because when
first Marshallese
began to develop nodules, they were given prophylactic thyroid horfone (T,) to inhibi
the development of more neoplasms.
It has subsequently been sh
people became at least mildly hypothyroid after many years if
supplement (Larsen,et al, including this principle investigation,
that many of these
were not given Ty
press).
Asnear
‘as we can tell, most of the Marshallese have taken the Ty tablets
taken, the T, levels (at first PBI's) have been at a respectable 1
duals.
In spite of the administration of Ty for more than 15 yearp, we have continue
to find new lesions at almost every armmual examination of these
observations have prompted same skepticism as to whether TSH i
T, adminstration had been as successfully followed as was inten
sed people.
The
neoplasms or whe
Using the rat mod
in which neoplasms were expected to develop, we have used a very
itive rat TSH as
on serum collected at the time animals were sacrificed. (Experim
al data still imec”
Radioimmmoassay for TSH and its Application
To The Study of Neoplasm Induction
We have modified and tested a radioimmmoassay (RIA) for rat |TSH in our laborat:
under this contract.
This has been done according to the method df Kieffer, et al,
1974, using NIAMD materials, and with advise of Dr. P. Reed Larsem who has been a
collaborator on the Marshallese work.
laboratory and is reliable.
Our assay has become well
The NIAMD Rat TSH:
iodination and RAT TSH RP I-2 for standard.
I-2 (potency 35
Our range of normal
qstablished in our
].U./mg) was used f
Yalues on a large
number of male control animals was 40 to 800 ng/ml with a mean of [412 SD ~ 263 ng/ml
1”)