[Behavior of triiodothyronine, tetraiodothyronine and thyrotropin during the TRH test]

Much confusion seems to exist on the timing and intensity of thyroid hormones (T4 and T3) response to TRH. As a first approach to the problem, the Authors performed TRH test in 5 healthy women. TSH showed a significant increase immediately after the TRH injection and kept high until the 90th minute. T3 decreased at first-still not significantly--then increased steadily and at 60 min it reached values significantly higher than the basal ones. Some increase was seen for T4 too, but it did not show to be statistically significant within 180 minutes. The Authors give revelance to the significance of precious (60 min) T3 increase in such a small casuistry.