産褥婦におけるTSHおよびPRL分泌

抄録

It has been reported that TRH is able to secrete not only TSH but also prolactin. As a method to elucidate this relationship, the response of TSH and prolactin secretion to TRH was observed in puerpera in which the serum prolactin level was elevated, but serum TSH level remained at a normal level. Following TRH administration, serum prolactin and TSH levels were observed for 2 hours.
In puerpera, the serum prolactin level before TRH administration was 73.4 ± 52.0 ng/ml, and this value was extremely high as compared with 6.7 ± 4.9 ng/ml in normal female subjects. Following TRH administration, serum prolactin elevated to an extremely high level in puerpera as compared with that in normal female subjects.
In puerpera, the serum TSH level before TRH administration was less than 3.4 μU/ml, and this value was the same or less than 3.1 μU/ml in normal female subjects. However following TRH administration, in puerpera serum TSH elevated to a significantly high level as compared with that in normal female subjects. Namely, an increased TSH response to TRH was observed in puerpera with high prolactin levels.
These results suggest two hypotheses : firstly, there is an increased requirement for both prolactin and TSH secretion in puerpera, secondly, there is a latent hypothyroid state in puerpera.