Friday, December 5, 2008

Redox Reactions and Growth Plates

NAD+ is involved in osteoblast pathology.  NAD+ can stimulate osteoblast differentiation.

COL2A1 gene expression is upregulated by SIRT1 and NAD+ is a limiting factor for it.  SIRT1 knockout mice are smaller than normal mice.  Caloric restriction increases SIRT1 levels and that may be responsible for catch up growth.

Initiation of endochondral calcification is related to changes in the redox state of hypertrophic chondrocytes.

"[We] relate the concentrations of NADH and NAD+ to stages of chondrocyte maturation. A dramatic increase was found in the relative concentration of reduced pyridine nucleotides in the hypertrophic zone. On either side of this zone, in proliferating and calcifying cartilage, there was a decrease in NADH fluorescence, and the NADH/NAD+ ratio was depressed. The finding that NADH accumulated in the tissue zone associated with the earliest deposition of bone mineral supports the hypothesis that a change in the redox state initiates tissue mineralization."

Still cant get this full paper

No comments:

Post a Comment