[Changes in blood levels of the pituitary-thyroid axis observed during therapy with protirelin ++ in hospitalized euthyroid patients with cerebrovascular disease].

The effects of a TRH-T (protireline tartrate) treatment at a dose of 2 mg/day for 3 weeks on the serum levels of the pituitary-thyroid axis hormones, have been studied in a randomized group of 10 elderly euthyroid hospitalized patients with cerebrovascular disease. At the end of the treatment an 8.3% mean increase of serum T3 level and a 12.5% mean increase of serum FT3 level (p less than 0.02 in both cases) have been observed. At the same time a 34% mean decrease of the basal TSH (p less than 0.05) and a 26% mean decrease of the delta-TSH after TRH-test (p less than 0.025) have been noted. However, the hormone concentrations changes never exceeded the normal values. In a randomized group of 9 hospitalized untreated patients with cerebrovascular disease used as controls (matched for age and sex), no significant changes of studied hormones have been recorded. In the treated patients, one week after the withdrawal of therapy serum levels of thyroid hormones and TSH went back to the levels observed before treatment. TRH-T seems to cause these modest hormone changes by decreasing the number of TRH receptors and the activity of TSH secreting cells. Nevertheless, the presence of the normal feedback in the pituitary-thyroid axis, allows a good tolerance to such a treatment.