Intranasal Thyrotrophin Releasing Hormone Is a Potent Stimulus for TSH Release in Man (Comparison With Intravenous and Oral Trh)

Abstract

Intranasally administered TRH was tested and compared to i.v. and oral TRH in respect to its efficacy of TSH stimulation and thereby the stimulation of thyroid reserve. TSH release after nasal application is as prompt as after the i.v. route, reaching a peak at 20 to 30 min. After that, however, compared to the i.v. administration its stimulatory effect is prolonged, lasting over 3 h. At the dose used in this study the peak TSH response after intranasal TRH administration was 14.7 +/- 1.6 mU/l compared to 8.4 +/- 1.4 and 23.1 +/- 4.4 mU/l after i.v. and oral administration respectively (P less than 0.005). Intranasal application of TRH is as potent as i.v. or oral TRH for the stimulation of thyroid reserve. At 3 h a marked increase of T3 and a smaller elevation of FT4 is observed (delta T3 = 48.4%, delta FT4 = 31.6%). The nasal peptide was well tolerated locally and systemic side effects were comparable to those of i.v. TRH. This form of application offers a practical advantage by avoiding intravenous injections. Its diagnostic potential in investigation of thyroid disease and its possible therapeutic application have yet to be elucidated.

Thyrotropin-releasing hormone in geriatric patients: intravenous versus intranasal application

“…Although the adverse reactions were not severe in our patients, they would have been probably more significant if we had not performed the test in the recumbent position. Also, the lying or half sitting position of the geriatric patients may explain the lower fre¬ quency of adverse reactions in our investigation series as compared with reported data (Vogt et al 1978;Schäfgen et al 1983;Schurr et al 1985;Staub et al 1985).…”

Estimation of Tissue Hypothyroidism by a New Clinical Score: Evaluation of Patients with Various Grades of Hypothyroidism and Controls1

“…fT 4 (normal, 8.0 -27 pmol/L) and T 3 (0.9 -3.0 nmol/L) were measured by RIA (10,11). Before introduction of this second generation TSH assay, we used a conventional RIA for TSH determinations.…”

Pharmacokinetics of Gonadotropin-Releasing Hormone and Its Analogs

“…Polypeptides with mol wt up to 2000 (76)(77)(78) are pharmacologically active via the IN route whereas larger peptides (mol wt 2000-6000) are reliably absorbed only with the addition of absorption enhancers (56,71,77,(79)(80)(81). In addition to the effect of molecular size, transnasal absorption is greater for lipophilic compounds (82), and the addition of a surfactant enhanced the transnasal bioavailability of a hydrophilic GnRH agonist 15-fold (34, 35).…”