Bone biomarkers of ovariectomised rats after leptin therapy

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.

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) received a single dose of buffer solution i.p. daily for eight weeks. Group II (ovariectomy group) received a single dose of buffer solution i.p. daily for eight weeks. 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 (10 µg/kg body weight) i.p. daily for eight weeks. The obtained serum is required for determination of: Serum osteocalcin, alkaline phosphatase, calcium and phosphorous levels.

The obtained data revealed that treatment with alendronate or leptin caused a significant decrease of serum osteocalcin, specific bone alkaline phosphatase and urinary deoxypyridinoline levels compared to ovariectomy group, and there was no significant difference between both drugs.

Leptin prevents ovariectomy induced increases in bone turnover in rats. Leptin therapy has a significant effect in treatment of ovariectomy induced osteoporosis in rats (Tab. 1, Ref. 32).