RESUMO
Serum TSH (Thyroid Stimulating Hormone) was measured before and 30 minutes after a 200 microgram intravenous TRH (Protiréline*) injection in 270 patients. These patients have been treated for one year at least, by a suppressive thyroid therapy after thyroidectomy for a differentiated thyroid carcinoma. 314 tests were performed. We used an ultrasensitive TSH method (Ciba-Corning-Diagnostics). The normal range (mean :1.68 mUI/l; range: 0.45 to 3.80 mUI/l) was determined in 116 euthyroid patients. Minimal response to TRH was studied in 35 untreated patients with hyperthyroidism (TSH TO: less than 0.30 mUI/l and delta TSH: less than 0.09 mUI/l). There was a relationship (r = 0.916) between TSH response 30 minutes after TRH stimulation (T30) and basal TSH value: in a logarithmic scale (fitting of the data by a bi-gaussian model). TRH tests were classified too, by basal TSH values (TO) and delta TSH (TSH at T30-TSH at TO). In 201 tests in which TO TSH was less than 0.30 mUI/l (maximal value in hyperthyroidism), 50 showed a delta TSH higher than 0.15 mUI/l (25% of the cases) and in 6 cases (3%), delta TSH was even higher than 2.0 mul/l; in 67 of the 75 tests (89.3%) where TSH TO is less than 0.15 mUI/l, delta TSH is no (less than 0.15 mUI/l). In 93 tests where TO TSH was upper than 0.45 mUI/l (minimal value in euthyroidism), delta TSH was higher than 2.0 mUI/l in 87 cases (93.6%).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Carcinoma/tratamento farmacológico , Hormônios Tireóideos/uso terapêutico , Neoplasias da Glândula Tireoide/tratamento farmacológico , Hormônio Liberador de Tireotropina/farmacologia , Tireotropina/sangue , Adolescente , Adulto , Idoso , Carcinoma/sangue , Carcinoma/fisiopatologia , Feminino , Humanos , Hipertireoidismo/sangue , Hipertireoidismo/fisiopatologia , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Neoplasias da Glândula Tireoide/sangue , Neoplasias da Glândula Tireoide/fisiopatologia , Hormônio Liberador de Tireotropina/administração & dosagemRESUMO
1. In frog atrium, Cs ions block both the inward rectifier iK1 and the carbachol induced K current iCch. 2. Both iK1 and iCch display a high affinity for Cs with a K0.5 of 4 X 10(-5) M for iK1 and of 8 X 10(-5) M for iCch at V = -50 mV. 3. Block of both iK1 and iCch is strongly voltage dependent. When fitted by the block model of Woodhull (1973), delta is greater than 1 for the two currents. 4. From these similarities, action of Cch on frog atrium K permeability could be interpreted as a modification of iK1.
