Increases in callus formation and mechanical strength of healing fractures in old rats treated with parathyroid hormone.
We studied the effects of intermittent administration of parathyroid hormone (PTH(1-34)) on callus formation and mechanical strength of tibial fractures in 27-month-old rats after 3 and 8 weeks of healing. 200 microg PTH(1-34)/kg was administered daily during both periods of healing, and control animals with fractures were given vehicle. At 3 weeks, PTH treatment increased maximum load and external callus volume by 160% and 208%; at 8 weeks, by 270% and 135%. It also enhanced callus bone mineral content (BMC) by 190% and 388% (3 and 8 weeks). From week 3 to week 8, callus BMC increased by 60% in the vehicle-injected animals, and by 169% in the PTH-treated animals. In the contralateral intact tibia, PTH treatment increased BMC by 18% and 21% (3 and 8 weeks). No differences in body weight were found between the vehicle-injected and the PTH-treated animals during the experiment. In conclusion, PTH treatment enhances fracture strength, callus volume and callus BMC after 3 and 8 weeks of healing.
Andreassen
T T
TT
Department of Connective Tissue Biology, Institute of Anatomy, University of Aarhus, Denmark. tta@ana.au.dk
Fledelius
C
C
Ejersted
C
C
Oxlund
H
H
D000818:Animals; D001696:Biomechanical Phenomena; D001835:Body Weight / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D002146:Bony Callus / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D017102:Fracture Healing / Q000187:drug effects*; D010281:Parathyroid Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013978:Tibial Fractures / Q000503:physiopathology
D010281:Parathyroid Hormone