We aimed to investigate the effects of the aromatase inhibitor letrozole on femur fracture and serum levels of alkaline phosphatase (ALP), calcium and phosphate in female rats. Intact 32 Sprague-Dawley female rats were divided into four groups (n=8): control, letrozole 0.2 , letrozole 1 (treatment of 0.2 and 1 mg/kg for six weeks) and recovery (letrozole-treated 1 mg/kg for six weeks then allowed to recover for two weeks). Besides, 24 ovariectomized rats were divided into three groups (n=8): ovariectomized+control, ovariectomized+letrozole and ovariectomized+letrozole+ estradiol (10 μg/rat). After experimental period, rats’ femur bones were removed for biomechanical studies following decapitation. Serum ALP, calcium and phosphate were measured. Biomechanical values, ALP and phosphate significantly increased by letrozole in a dose-dependent manner (p<0.05) while calcium levels and net bone area decreased (p<0.05). Ultimate strength was positively correlated with ALP and phosphate and negatively correlated with calcium. The results indicate that letrozole may increase risk of bone fracture and affect bone biomarkers such as ALP, calcium and phosphate in both intact and ovariectomized rats.

中文翻译：

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来曲唑对雌性大鼠骨生物标志物和股骨骨折的影响。

我们旨在研究芳香酶抑制剂来曲唑对雌性大鼠股骨骨折和血清碱性磷酸酶 (ALP)、钙和磷酸盐水平的影响。将完整的 32 只 Sprague-Dawley 雌性大鼠分为四组 (n=8)：对照组、来曲唑 0.2、来曲唑 1（0.2 和 1 mg/kg 治疗六周）和恢复（来曲唑治疗 1 mg/kg 六周）然后允许恢复两周）。此外，将24只去势大鼠分为三组（n=8）：去势+对照、去势+来曲唑和去势+来曲唑+雌二醇（10 μg/大鼠）。实验结束后，将大鼠的股骨取出，进行斩首后的生物力学研究。测量血清ALP、钙和磷酸盐。生物力学值，来曲唑以剂量依赖性方式显着增加 ALP 和磷酸盐（p<0.05），而钙水平和净骨面积减少（p<0.05）。极限强度与 ALP 和磷酸盐呈正相关，与钙呈负相关。结果表明，来曲唑可能会增加骨折风险，并影响完整和去卵巢大鼠的骨生物标志物，如 ALP、钙和磷酸盐。