Time course of bone biomechanical parameters in ovariectomized mice

Abstract

Four-week-old female ddY mice were ovariectomized or sham-operated, and biochemical and biomechanical measurements were performed to examine timedependent changes in quality and quantity of bone after the operations. The body weight and the femoral length increased time dependently and no difference was observed between the ovariectomized and the sham-operated mice. On the other hand, increase in the uterine weight was completely suppressed in the ovariectomized mice, although the uterine weight of the sham-operated mice increased in a timedependent manner. The femoral weight of both the shamoperated and the ovariectomized mice tended to increase time dependently within 4 weeks after the operations. However, the increase in the ovariectomized mice was mild and stopped at 5 weeks after the operation. Calcium and hydroxyproline content, failure load, and stiffness of femur were highly correlated with femoral weight in both ovariectomized and shamoperated mice. The yield energy of femur correlated with the femoral weight in the sham-operated mice but not in the ovariectomized mice. The increase in the yield energy of the ovariectomized mice was completely suppressed after the operation in spite of time-dependent gain in femoral weight. Therefore, the yield energy of femur is the best index for morbidity of osteoporosis of all these parameters described in this study.

Suppressive effect of truncated norzoanthamine (TZ) for bone loss in an osteoporosis mouse model

“…OVX mice have been used as an osteoporosis animal model due to the decreasing bone volume and bone mechanical parameters observed in this model. Reportedly, NZ administration suppresses bone loss and maintains bone mechanical parameters [3,7]. Compared with the sham group, bone parameters (BV/TV, Tb.Th., Tb.N.)…”

“…To induce osteoporosis, 4-week old female ddy mice were ovariectomized (OVX) or sham-operated (Sham) under pentobarbital and isoflurane anesthesia [7]. The mice were divided into 7 groups: Sham group, OVX control group, OVX 17 beta-estradiol (E2 0.08 mg/kg/day) group, and TZ (0.004, 0.02, 0.1, 0.5 mg/kg/day) groups.…”

Zoanthamines, Antiosteoporotic Alkaloids

“…Furthermore, there is no in vitro assay system to evaluate the mechanical strength of bone and its morphology. Thus, we have developed an in vivo assay system using an osteoporosis model in mice [9]. This postmenopausal osteoporosis model using ovariectomized mice is useful for evaluating antiosteoporotic drugs, since several parameters are clearly decreased within 4 or 5 weeks after the ovariectomy.…”

Toward the Synthesis of Norzoanthamine: Building Carbocyclic Core by a Transannular Michael Reaction Cascade

“…3 This property was characterized by suppression of the loss of bone weight and bone strength of ovariectomized mice, animal models that mimic postmenopausal osteoporosis. 4 When orally administered in the form of its HCl salt, norzoanthamine suppressed the loss of the trabecullar bone and induced thickening of the cortical bone of ovariectomized mice at a dosage of 2 mg/kg/day with no obvious side effects over a period of four weeks. While norzoanthamine appears to function through a mechanism that is different from that of estrogen in inhibiting osteoporosis, 3 its detailed mode-of-action remains unknown.…”

“…Norzoanthamine is arguably the most notable of this group due to its potent antiosteoporotic effect . This property was characterized by suppression of the loss of bone weight and bone strength of ovariectomized mice, animal models that mimic postmenopausal osteoporosis . When orally administered in the form of its HCl salt, norzoanthamine suppressed the loss of the trabecullar bone and induced thickening of the cortical bone of ovariectomized mice at a dosage of 2 mg/kg/day with no obvious side effects over a period of four weeks.…”