The Effects of Ovariectomy and Naproxen Treatment on the Strength of Femoral Midshaft and Molar Alveolar Region in Rats

Abstract

SUMMARY:The goal of the present study was to investigate the effects of ovariectomy and naproxen treatment on both femoral and mandibular bone mass and biomechanical competence. Sprague-Dawley rats were used and divided into five groups: baseline, sham ovariectomized, ovariectomized, sham ovariectomized + naproxen treatment, ovariectomized + naproxen treatment. Mandibles and femurs of the rats were extracted and bone mineral density of the extracted specimens were determined. The volumes and ash weights of the femurs and mandibles were estimated. Maximum loads of the femurs and mandibles were determined by using a three point bending test. Ovariectomy decreased bone mineral density of the femoral midshaft, however naproxen prevented this decrease. Neither ovariectomy nor naproxen treatment affected the BMD in the molar alveolar region. Maximum load was found significantly decreased in the femoral midshaft, however, naproxen treatment prevented this decrease. Maximum load of the molar alveolar region did not significantly change. Naproxen prevents the strength characteristics of femoral midshaft afforded by ovariectomy. However, neither ovariectomy nor naproxen has an effect on the molar alveolar region of the mandible.

Effects of Leptin on Metabolic Bone Turnover in Ovariectomy Rats

“…All the animals were cared with analgesia and antibiotics equally after surgery. The success of ovariectomy was confirmed at necropsy by failure to detect ovarian tissue and by observation of marked atrophy of the uterine horns (13,11).…”

“…Bilateral OVX was performed using a dorsal approach under i.p. sodium pentobarbital (40 mg/kg body weight) anesthesia (11). A skin incision (about 0.5-1.0 cm long) was made midway between the last rib and the cervix and about 1 cm lateral to the spinal muscles.…”

Bone biomarkers of ovariectomised rats after leptin therapy

“…Bilateral OVX was performed using a dorsal approach under i.p. sodium pentobarbital (40 mg/kg body weight) anesthesia (Turkozan et al, 2009). A skin incision (about 0.5-1.0 cm long) was made midway between the last rib and the cervix and about 1 cm lateral to the spinal muscles.…”

“…All the animals were cared with analgesia and antibiotics for equally after surgery. The success of ovariectomy was confi rmed at necropsy by failure to detect ovarian tissue and by observation of marked atrophy of the uterine horns (Li et al, 2002, Turkozan et al, 2009). …”

“…Peripherally, leptin interacts with bone marrow stromal cells, osteoblasts, and osteoclasts to increase bone mass (Jackson et al, 2011). Leptin increases both expression of osteogenic genes in stromal cells (van Marken et al, 2009) and osteoblast proliferation and decreases osteoclastogenesis (Cirmanová et al, 2008). Centrally, leptin inhibits bone formation by binding to its receptors located in hypothalamus and thereby activating the sympathetic nervous system (SNS), which requires the adrenergic β2 receptors (Adrb2) expressed in osteoblasts (He et al, 2011).…”