Kimura Shuichi, Sasase Tomohiko, Ohta Takeshi, Matsushita Mutsuyoshi
Biological/Pharmaceutical Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Takatsuki, Osaka 569–1125, Japan.
J Vet Med Sci. 2011 Aug;73(8):1025-9. doi: 10.1292/jvms.11-0064. Epub 2011 Apr 14.
The Spontaneously Diabetic Torii-Lepr(fa) (SDT- fa/fa) rat is a new model of obese type 2 diabetes. The female SDT-fa/fa rat shows obesity, hyperglycemia and hyperlipidemia from a young age. However, it is not known whether diabetes and estrogen deficiency can lead to bone abnormalities in the female SDT-fa/fa rat. The objective of the present study was to investigate the effects of ovariectomy (OVX) on bone metabolism and bone mineral density (BMD) in the female SDT-fa/fa rat. Female Sprague-Dawley rats were used as control animals. The BMDs of the whole tibia and fifth lumbar (L5) vertebral body were analyzed at 30 weeks after OVX. Serum osteocalcin, a bone formation marker, and urine deoxypyridinoline (DPD), a bone resorption marker, were sequentially analyzed before and at 5, 15 and 30 weeks after OVX. Serum osteocalcin and urine DPD levels were lower in SDT-fa/fa rats than in control rats before OVX. Both serum osteocalcin and urine DPD levels were elevated in control rats 5-30 weeks after OVX, but only the urine DPD levels were elevated in SDT-fa/fa rats 5-30 weeks after OVX. SDT-fa/fa rats showed a decrease in the BMDs of the whole tibia and L5 vertebral body compared with control rats. OVX decreased the BMDs of the whole tibia and L5 vertebral body in control rats, but not in SDT-fa/fa rats. These data suggest that estrogen deficiency is not a risk factor for bone loss in type 2 diabetes mellitus.
自发性糖尿病Torii-Lepr(fa)（SDT-fa/fa）大鼠是肥胖型2型糖尿病的一种新模型。雌性SDT-fa/fa大鼠从年轻时就表现出肥胖、高血糖和高血脂。然而，糖尿病和雌激素缺乏是否会导致雌性SDT-fa/fa大鼠出现骨骼异常尚不清楚。本研究的目的是探讨卵巢切除术（OVX）对雌性SDT-fa/fa大鼠骨代谢和骨密度（BMD）的影响。雌性Sprague-Dawley大鼠用作对照动物。在OVX后30周分析全胫骨和第五腰椎（L5）椎体的骨密度。在OVX前以及OVX后5、15和30周依次分析血清骨钙素（一种骨形成标志物）和尿脱氧吡啶啉（DPD，一种骨吸收标志物）。在OVX前，SDT-fa/fa大鼠的血清骨钙素和尿DPD水平低于对照大鼠。在OVX后5 - 30周，对照大鼠的血清骨钙素和尿DPD水平均升高，但在OVX后5 - 30周，SDT-fa/fa大鼠仅尿DPD水平升高。与对照大鼠相比，SDT-fa/fa大鼠的全胫骨和L5椎体骨密度降低。OVX降低了对照大鼠全胫骨和L5椎体的骨密度，但对SDT-fa/fa大鼠没有影响。这些数据表明，雌激素缺乏不是2型糖尿病患者骨质流失的危险因素。
