Dr Carmichael is presently affiliated with Carmichael Torrance Diagnostic Services, West Yorkshire, UK. The work was performed at the Department of Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medcine, Ghent University, Belgium. A portion of these results was presented as a research abstract at the ECVIM-ca Annual Meeting in Uppsala, Sweden, 2003.
Effect of Storage of Reconstituted Recombinant Human Thyroid-Stimulating Hormone (rhTSH) on Thyroid-Stimulating Hormone (TSH) Response Testing in Euthyroid Dogs
Article first published online: 28 JUN 2008
Journal of Veterinary Internal Medicine
Volume 20, Issue 4, pages 812–817, July 2006
How to Cite
Roover, K. D., Duchateau, L., Carmichael, N., van Geffen, C. and Daminet, S. (2006), Effect of Storage of Reconstituted Recombinant Human Thyroid-Stimulating Hormone (rhTSH) on Thyroid-Stimulating Hormone (TSH) Response Testing in Euthyroid Dogs. Journal of Veterinary Internal Medicine, 20: 812–817. doi: 10.1111/j.1939-1676.2006.tb01790.x
- Issue published online: 28 JUN 2008
- Article first published online: 28 JUN 2008
- Revised September 29, 2005; October 28, 2005; Accepted December 6, 2005
- Thyroid function test;
Bovine thyrotropin (bTSH) stimulation testing has long been considered the gold standard for diagnosis of canine hypothyroidism. Unfortunately, bTSH is no longer commercially available. Recently, the use of recombinant human thyrotropin (rhTSH) to perform thyroid-stimulating hormone (TSH) stimulation testing in dogs was described. The cost of an rhTSH vial (1.1 mg) limits the practical use of this product. The study reported here was performed to determine the effects of storing rhTSH on the post-TSH increase of serum total (TT4) and free (FT4) thyroxine concentrations during TSH stimulation testing in 12 euthyroid Beagles in a crossover trial. Three TSH tests with recombinant human thyrotropin (rhTSH; 91.5 μg IV) were performed on each dog during 3 different periods: 1 with freshly reconstituted rhTSH (fresh); 1 with rhTSH, reconstituted and stored at 4°C for 4 weeks (refrigerated); and 1 with rhTSH, reconstituted and frozen at-20°C for 8 weeks (frozen). Blood samples for determination of TT4 and FT4 concentrations were collected before and 4 and 6 hours after rhTSH administration. There was no significant difference in TT4 or FT4 concentration after stimulation with fresh, refrigerated, and frozen rhTSH. Furthermore, there was no significant difference between TT4 or FT4 serum concentration observed 4 and 6 hours after rhTSH administration. In conclusion, reconstituted rhTSH can be stored at 4°C for 4 weeks and at-20°C for 8 weeks without loss of biological activity, allowing clinicians to perform more TSH response tests per vial.