Effect of recombinant human thyroid stimulating hormone on serum thyroxin and thyroid scintigraphy in euthyroid cats.
This study investigated the thyroidal response to administration of recombinant human thyroid stimulating hormone (rhTSH) by means of serum total thyroxine (TT(4)) concentration and pertechnetate uptake by the thyroid gland in six healthy euthyroid spayed female cats. A pertechnetate scan was performed on day 1 to calculate thyroid/salivary gland (T/S) uptake ratio. On day 3, 25 microg rhTSH was injected intravenously. Six hours later the thyroid scan was repeated as on day 1. Blood was drawn for serum TT(4) measurement prior to injection of rhTSH and performance of the pertechnetate scan. Statistically significant differences in mean serum TT(4) concentration, T/S uptake ratio before and 6h after rhTSH administration and T/S uptake ratio between left and right lobes were noted. We can conclude that 25 microg rhTSH increases pertechnetate uptake in the thyroid glands of cats, this should be taken into account when thyroid scintigraphy after rhTSH administration is interpreted.
Department of Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. ingrid.vanhoek@ugent.be
Ingrid M
IM
van Hoek
Kathelijne
K
Peremans
Eva
E
Vandermeulen
Luc
L
Duchateau
Kris
K
Gommeren
Sylvie
S
Daminet
D000818:Animals; D002371:Cat Diseases / Q000097:blood / Q000175:diagnosis; D002415:Cats / Q000097:blood*; D005260:Female; D007037:Hypothyroidism / Q000097:blood / Q000175:diagnosis / Q000662:veterinary; D011877:Radionuclide Imaging / Q000379:methods / Q000662:veterinary; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000493:pharmacokinetics*; D013670:Sodium Pertechnetate Tc 99m / Q000494:pharmacology*; D013961:Thyroid Gland / Q000187:drug effects* / Q000502:physiology; D013972:Thyrotropin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D013974:Thyroxine / Q000097:blood*; D013997:Time Factors
D011994:Recombinant Proteins; D013972:Thyrotropin; D013670:Sodium Pertechnetate Tc 99m; D013974:Thyroxine