Continuous PTH and PTHrP Infusion Causes Suppression of Bone Formation and Discordant Effects on 1,25(OH)2Vitamin D

@article{Horwitz2005ContinuousPA,
  title={Continuous PTH and PTHrP Infusion Causes Suppression of Bone Formation and Discordant Effects on 1,25(OH)2Vitamin D},
  author={Mara J. Horwitz and Mary Beth Tedesco and Susan M. Sereika and Mushtaq Ahmad Syed and Adolfo Garc{\'i}a-Oca{\~n}a and Alessandro Bisello and Bruce W Hollis and Clifford J. Rosen and John J. Wysolmerski and Pamela Dann and Caren M. Gundberg and Andrew F. Stewart},
  journal={Journal of Bone and Mineral Research},
  year={2005},
  volume={20}
}
Osteoblast activity and plasma 1,25(OH)2vitamin D are increased in HPT but suppressed in HHM. To model HPT and HHM, we directly compared multiday continuous infusions of PTH versus PTHrP in humans. Continuous infusion of both PTH and PTHrP results in marked and prolonged suppression of bone formation; renal 1,25(OH)2D synthesis was stimulated effectively by PTH but poorly by PTHrP. 
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TLDR
PTHrP efficacy as an anabolic agent to prevent microgravity-induced cell death in TOs is confirmed and pulsatile treatment with P THrP1-36 not only reversed a large proportion of 0g-induced effects in Pthrp+/+ TOs but maintained viability over 6-week exposure to microgravity.
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TLDR
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