Effects of Different Doses of Dexamethasone on Bone Mineral Density and Body Composition in Rats / 天津医药

ABSTRACT

Objective To investigate the effects of different doses of dexamethasone (Dex) on bone mineral density (BMD) and body composition in Sprague-Dawley (SD) rats. Methods Forty 3-month-old female SD rats were divided into four groupscontrol group (Cont, saline), low dose Dex group (LDG, 1 mg/kg), medium dose Dex group (MDG, 2.5 mg/kg) and high dose Dex group (HDG, 5 mg/kg). Ten rats for each group. Dex was injected intramuscularly twice a week. The values of BMD and body composition were measured by DEXA densitometer at the beginning and 4-week of treatment. Results The body weights of different doses of Dex intervention groups were decreased after 1 to 4-week intervention compared with those of Cont group (P<0.01). After 4-week intervention, the total BMD, femur BMD, total bone mineral content (BMC), to-tal fat mass, trunk fat mass and leg fat mass were significantly increased in Cont group (P<0.01), while the total lean mass, trunk lean mass were significantly decreased (P<0.01). The total BMC, femur BMD, leg lean mass, leg fat mass were signifi-cantly lower in LDG group and MDG group than those of Cont group (P<0.05). The femur BMD, leg fat mass were signifi-cantly lower in LDG group and MDG group than those of HDG group (P<0.05). Conclusion The doses of 1 mg/kg and 2.5 mg/kg Dex have greater impact on the femur BMD and the leg composition in SD rats than that of Dex (dose of 5 mg/kg ).