ABSTRACT
[Summary] 45 male SD rats with 4 week old were assigned to 3 groups after normal feedstuff for 2 weeks:control group(n=15), diabetic group(n=15), and calcitriol group(n=15).Diabetic rat model were induced using intraperitoneal injection with streptozotocin( STZ) after 12 h fasting.Calcitriol group and diabetic group were treated with calcitriol for 24 weeks.Femoral biomechanics indexes were measured at end of the study.Total 30 SD rats ( 10 rats of each groups) were analyzed.Compared to normal controls, the rats in diabetic group had lower body weight [(437.02±18.66vs267.93±15.64)g,P<0.05],decreasedserumcalciumconcentration[(2.89±0.31vs2.60 ±0.38) mmol/L, P<0.05], and increased serum phosphorus concentration[(2.21 ±0.35 vs 2.80 ±0.66) mmol/L, P<0.05].At the end of the study, the ultimate force[(98.07 ±2.94 vs 70.87 ±5.75) N, P<0.05], ultimate displacement[(0.66 ±0.02 vs 0.51 ±0.02) mm, P<0.05], Young′s modulus[(139 188.51 ±10 617.69 vs 81 969.06 ±6 393.21) N/mm2, P<0.05], and modulus for toughness[(22 492.59 ±2 429.15 vs 8 292.87 ± 1 291.43) N/mm2 , P<0.05 ] of diabetic group were significantly lower than normal control group.However, calcitrol could reverse these changes at some extent.SD rats with diabetes had significant disorder of bone metabolism and decreased bone strength.Calcitriol could improve the decreased bone strength in diabetic rats.