Use of recombinant human thyroid-stimulating hormone for thyrotropin stimulation testing in euthyroid ferrets

Area of Science:

• Veterinary Endocrinology
• Diagnostic Testing in Animals

Background:

• Thyroid-stimulating hormone (TSH) is crucial for regulating thyroid hormone production.
• Assessing thyroid function in ferrets often requires a reliable stimulation test.
• Recombinant human TSH (rhTSH) offers a potential tool for such assessments.

Purpose of the Study:

• To determine the efficacy of intramuscular (IM) administration of rhTSH in stimulating plasma total thyroxine (T4) concentrations in euthyroid ferrets.
• To establish reference ranges for T4 response following rhTSH stimulation in this species.

Main Methods:

• An evaluation study involving 25 healthy, euthyroid ferrets (14 female, 11 male) from two distinct populations.
• Ferrets received a single 100 μg IM injection of rhTSH.
• Plasma T4 concentrations were measured immediately before and 4 hours after rhTSH administration.

Main Results:

• A significant increase in plasma T4 concentrations was observed 4 hours post-rhTSH injection (mean increase of 35%).
• All ferrets exhibited elevated T4 levels after stimulation, with no significant difference between sexes.
• Pre- and post-stimulation T4 levels differed significantly within the study population.

Conclusions:

• Intramuscular rhTSH administration is a viable method for thyrotropin stimulation testing in ferrets.
• A post-injection T4 increase of approximately 30% at 4 hours is indicative of a euthyroid state in ferrets following rhTSH stimulation.