Fluid space in bone.

This paper reviews the extraction of solutes through capillaries in bone, by means of outflow dilution techniques in the canine tibia. Solutes leave capillaries in bone by passive diffusion dependent on molecular size. The fluid space in bone is also examined by means of analyzing washout curves of radioactive substances. It is proposed that there are 4 definable compartments in bone; a vascular space, a perivascular fluid space a bone fluid space and a bone space. The relevance of these spaces is in bone mineral short and long term ion exchange activity.