Effects of Leptin on Metabolic Bone Turnover in Ovariectomy Rats

Abstract

Introduction. Under physiological conditions, maintenance of skeletal mass is the result of a tightly coupled process of bone formation and bone resorption. Disease states, osteoporosis included, arise when this delicate balance is disrupted such as in menopause.The aim of the present work was to study the effect of leptin supplementation on bone metabolism in ovariectomized adult female rats, by measuring indices of bone biomarkers.Material and methods. Forty adult female albino rats were chosen as an animal model for this study and divided into the four equal groups (n=10/group): Group I (control SHAM-operated group), Group II (ovariectomy group). Group III (alendronate group): Ovariectomized rats that received alendronate 0.1 mg/kg body weight i.p. daily for eight weeks. Group IV (leptin group): Ovariectomized rats that received leptin (10µg/kg body weight) i.p. daily for eight weeks. The obtained serum is required for determination of: Serum osteocalcin, alkaline phosphatase, calcium and phosphorus levels.Results. The obtained data revealed that: Treatment with alendronate or leptin caused significant decrease of serum osteocalcin, specific bone alkaline phosphatase and urinary deoxypyridinoline levels compared to ovariectomy group.Conclusions. The results obtained in the present study provide evidence that daily administration of leptin contributes significantly to improve the bone biomarkers of ovariectomy in rats. Leptin prevents ovariectomy induced increases in bone turnover in rats.

An NMR Metabolomic Study on the Effect of Alendronate in Ovariectomized Mice

“…Interestingly, weight gain of OVX mice over 23 weeks was higher than sham mice, even though their food intake was similar. It has previously been shown that estrogen deficiency can cause higher body weight and body fat deposition [27] , [28] , which may partially explain our results.…”

“…While the OVX mice receiving Fosamax treatment had a slightly elevated intake of chow compared with sham, intake was not significantly different between OVX and Fosamax-treated mice, suggesting that other factors may be responsible for the increased rate of weight gain of Fosamax mice. Interestingly, other studies in rats have shown that alendronate treatment results in higher body weight compared with OVX [28]. One possibility of the increased weight gain could be the neo-formation of bone tissue [41].…”