EFFECTS OF LEPTIN ON METABOLIC BONE TURNOVER IN OVARIECTOMY RATS.

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. [ABSTRACT FROM AUTHOR]