Protirelin (thyrotropin-releasing hormone) in thyroid gland: possible involvement in regulation of thyroid status.
OBJECTIVE
To establish the presence of the hypothalamic hormone protirelin (thyrotropin-releasing hormone, TRH) in human thyroid and to investigate whether the concentration of this peptide in the thyroid gland is sensitive to thyroid status.


METHODS
A procedure has been developed for the determination of TRH in the thyroid gland, distinct from TRH-like peptides which also react with TRH-antibody.


RESULTS
Human thyroid was shown to contain both authentic TRH and TRH-like peptides, a similar pattern was seen in a range of animal thyroids. The concentrations of TRH in non-active goiter thyroids were substantial (41.6-248 pmol.g-1); in contrast the thyroids from hyperthyroid patients contained very little TRH (0.01-2.52 pmol.g-1).


CONCLUSIONS
The physiologic role of TRH in the thyroid is not known but the large difference between the concentrations of this hormone in non-active and hyperactive thyroids suggests that thyroidal TRH may be involved in the regulation of thyroid status.
Smyth
D G
DG
Institute of Molecular Biology, Salzburg, Austria.
del Rio-Garcia
J
J
Wallnöfer
H
H
Gogl
H
H
Simma
W
W
Huber
A
A
Embacher
R
R
Fraser
H
H
Kreil
G
G
D006042:Goiter / Q000378:metabolism; D006801:Humans; D006980:Hyperthyroidism / Q000378:metabolism*; D013961:Thyroid Gland / Q000378:metabolism*; D013972:Thyrotropin / Q000378:metabolism; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism*; D013974:Thyroxine / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism
D014284:Triiodothyronine; D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin; D013974:Thyroxine