Rm. Kowalchuk et al., EFFECTS OF ETIDRONATE AND OOPHORECTOMY ON THE ZETA-POTENTIAL OF RAT BONE, Clinical orthopaedics and related research, (328), 1996, pp. 241-249
Recent clinical trials in osteoporotic patients show that cyclical eti
dronate therapy can increase vertebral bone mass and reduce the incide
nce of vertebral fractures, Stress generated potentials, which are the
orized to participate in a negative feedback arrangement regulating bo
ne and which are electrokinetic in origin, can be characterized in vit
ro by the zeta potential, a measure of electrical surface charge, Thus
, the possible effects of etidronate and oophorectomy on the zeta pote
ntial of bone were investigated with respect to bone remodeling, patho
physiology, and osteoporosis. Thirty-two oophorectomized and 48 sham o
ophorectomized rats received subcutaneous etidronate or saline, The ze
ta potential magnitude of the control group (sham oophorectomized, veh
icle only) increased 23.6% from age 6 to 10 months, a period of bone g
rowth, After 6 weeks of etidronate treatment, which decreased bone tur
nover, the zeta potential magnitude was decreased 14.9% (0.59 mV) comp
ared with that of controls, Decreased zeta potential magnitudes with e
tidronate treatment also were observed in sham oophorectomized groups
at 16 weeks and in oophorectomized groups at 6 and 16 weeks, but the d
ifferences were not statistically significant, A large bolus of etidro
nate had no effect, The zeta potential of bone is a dynamic quantity t
hat may correlate with bone growth or bone turnover, Whether it exerts
a causative effect or is a marker remains unknown.