Rm. Kowalchuk et Sr. Pollack, STRESS-GENERATED POTENTIALS IN BONE - EFFECTS OF BONE FLUID COMPOSITION AND KINETICS, Journal of orthopaedic research, 11(6), 1993, pp. 874-883
It is now generally accepted that stress-generated potentials (SGPs) a
t low frequencies are due to an electrokinetic phenomenon in the small
interior surfaces of bone and are directly proportional to the zeta p
otential, a property of the poorly characterized bone surface-bone flu
id interface. We hypothesized that this interface would be labile and
might explain the controversy over whether or not the polarity of SGPs
can invert under certain conditions. In this paper, the effects of al
terations in the steeping fluid on SGPs for 87 samples from 15 animals
were examined in four-point bending for steeping times of less-than-o
r-equal-to 65 h. Calcium and fluoride in distilled-deionized water and
constant ionic strength solutions produced concentration-dependent in
versions in the SGP sign. A new steady state was reached in approximat
ely 18 h. The effects of the fluoride anion (unlike the calcium cation
) apparently were reversible. The results strongly suggest that the ze
ta potential at the labile bone surface-bone fluid interface can under
go dramatic changes, not only in magnitude but also in sign. The resul
ts further suggest that the preparation of bone samples is critical to
the understanding of this interface in vivo, and they support the hyp
othesis that SGPs have a role in bone remodeling.