[Pharmacokinetics and pharmacodynamics of protirelin (TRH) in man].
Blood concentrations of thyrotropin-releasing hormone (TRH, Protirelin) were measured by a specific radioimmunoassay in 16 euthyroid subjects after intravenous (200 micrograms), nasal (2 mg) or oral (40 mg) administration of TRH. TRH blood levels peaked 2 min after i.v. administration (13,400 +/- 1,020 fmol/ml), 10 min after nasal (5,000 +/- 1,800 fmol/ml) and 150 min after oral (2,650 +/- 1,080 fmol/ml) administration. The degradation of TRH followed an exponential curve, giving a half-life of 6.5 min. The disappearance rate gave a "half-life" of 22 min in the nasal application group and of 31 min in the oral group. Maximal concentration of stimulated thyrotropin-stimulating hormone (TSH) always occurred 30 min after the peak TRH concentration without any correlation with the TRH concentration time integrals, suggesting that TSH secretion is dependent on a continually rising TRH blood level.
D000281:Administration, Intranasal; D000284:Administration, Oral; D000328:Adult; D006207:Half-Life; D006801:Humans; D007275:Injections, Intravenous; D011863:Radioimmunoassay; D013972:Thyrotropin / Q000097:blood; D013973:Thyrotropin-Releasing Hormone / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D013997:Time Factors
D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin
Pharmakokinetik und Pharmakodynamik von Protirelin (TRH) beim Menschen.