Transmembrane bone morphogenesis across multiple-walled diffusion chambers. New evidence for a diffusible bone morphogenetic property
M. R. Urist, R. Granstein, H. Nogami, L. Svenson and R. Murphy
Bone generation and regeneration are associated with a bone morphogen that
recruits mesenchymal cells for differentiation into bone. Experiments with
particulate bone matrix gelatin implanted in multiple-walled diffusion
chambers suggest that bone morphogen is a rapidly diffusible molecule, and
consists of a noncollagenous bone morphogenetic protein (BMP). When
particulate bone matrix gelatin is implanted inside of diffusion chambers
constructed of two to five membranes, ranging from 300 to 750 cu micronm in
total thickness, large deposits of bone develop on the outside. The volumes
of the deposits of new bone are inversely proportional to the thickness (or
distance) of transmission of the BMP. Transmission for long distances
through interstitial fluid can be accounted for by a low molecular mass
hydrophobic BMP, disseminated according to the laws of diffusion.
