Serum levels of thyrotropin, prolactin, growth hormone, triiodothyronine and thyroxine after oral administration of thyrotropin releasing hormone in hypothyroid and hyperthyroid patients.

After peroral administration of TRH there were found elevated responses of TSH and HPr in hypothyroidism but not in hyperthyroidism. While the basal levels of TSH were elevated in hypothyroidism and depressed in hyperthyroidism, no such difference has been found in the case of basal levels of HPr. After TRH stimulation the levels of HGH decreased especially in hyperthyroidism; in patients with acromegaly serum HGH level increased after TRH. Serum T4 increased only in euthyroid persons after 2 and especially 24 hours, but not in hyperthyroidism or hypothyroidism. Mean values of serum T3 were elevated after TRH in all three groups, but the difference was significant only in euthyroid subjects. FT4I was increased in euthyroid person after TRH stimulation.