Pharmacokinetics and pharmacodynamics following low dose TSH administration in aged ovariectomized rats

• Published in: The FASEB journal 2007-04, Vol.21 (5), p.A432-A432
• Main Authors: Huff, Michael R, Culm‐Merdek, Kerry E, Fogle, Robert, Gotschall, Russell, Sampath, Kuber, Sendak, Rebecca A, Andrews, Laura
• Format: Article
• Language: English
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.21.5.A432

Preclinical findings indicate that thyroid stimulating hormone (TSH) positively influences bone remodeling. For example, administration of low dose TSH prevents bone loss and restores bone mass in aged ovariectomized (OVX) Sprague‐Dawley rats. These studies were designed to characterize low dose rat TSH pharmacokinetics and pharmacodynamics in ovariectomized and control Sprague‐Dawley rats. Rat TSH (0, 0.1, 0.3, 1.0, 100 ug/rat) was administered to sham control and ovariectomized rats 12 weeks following surgery. Serum samples were collected at 1.0, 2.0, 4.0, 6.0, 8.0 hours following a single rat TSH dose for TSH, T4, and T3 analysis. Rat TSH pharmacokinetics were similar between control and OVX animals with a mean half‐life of 1.5 hours. Lower doses of TSH (0.1‐1.0 ug/rat) did not affect circulating T4 levels, whereas the high dose (100 ug/rat) significantly increased T4. Overall, these data show that doses of TSH which correlate to beneficial effects on bone remodeling, do not appear to change thyroid hormone homeostasis.