January 16, 2009

Understanding why aging bones heal less

U.S. researchers said they have unraveled crucial details on how aging causes broken bones to heal slowly -- or not at all.

In animal studies, published in the Journal of Bone and Mineral Research, found levels of the enzyme cycloxgenase 2 drop dramatically with age and confirmed healing ability lost with age can be rescued by manipulating the cycloxgenase 2 pathway.

The skeleton loses the ability to repair itself as we age, study corresponding author Dr. Regis O'Keefe of the University of Rochester Medical Center said in a statement. Our results position the cycloxgenase 2 pathway as one of several under exploration with the common goal of accelerating healing in aging humans, and with the potential to come together in future combination therapies.

Healing rates were compared between a group of young mice -- ages 7-9 weeks old -- and a group of old mice -- 52-56 weeks of age -- using imaging and gene expression studies.

The researchers also found the delayed fracture healing observed in aged mice could be rescued with local delivery of an experimental drug CP-734432 provided to the team by Pfizer Inc.