蓝光对维甲酸致骨质疏松大鼠的影响

Effect of blue light on osteoporosis induced by retinoic acid in rats

目的:探讨蓝光照射后维甲酸致大鼠骨质疏松模型的骨代谢指标及骨微结构的改变情况。方法:将24只9月龄SD大鼠随机分为正常组、模型组、蓝光1组和蓝光2组,每组6只。蓝光组和模型组每天用100 mg/kg的维甲酸连续灌胃14 d,正常组用同体积的蒸馏水灌胃14 d,14 d后各组均恢复正常饮食、饮水。正常组和模型组全程采用日光灯光照模式照射,蓝光1组和2组在维甲酸造模完成后分别采用蓝色光照模式(460 nm)照射14 d和21 d。非蓝光照射时日光灯照射补齐至总照射天数(35 d)。所有大鼠均于35 d后取眼眶血,测定血清钙、磷、碱性磷酸酶(alkaline phosphatase,ALP)、β-胶联降解物(β-bonded degradation products,β-CTX)和Ⅰ型前胶原氨基端肽(amino terminal peptide of procollagen type 1,P1NP)水平。采用CO2麻醉处死大鼠后取股骨,用microCT测定骨密度、骨小梁数量、骨小梁厚度和骨小梁分离度。结果:与正常组相比,模型组钙、磷、ALP、β-CTX和P1NP水平以及骨密度、骨微结构显著改变(P<0.01),说明造模成功。与模型组相比,蓝光1组的体质量、血钙水平、血磷水平、ALP、β-CTX,P1NP、骨小梁数量、骨小梁厚度、骨小梁分离度发生显著变化(P<0.05),但两组骨密度差异无统计学意义;蓝光2组大鼠的体质量、骨密度、骨微结构及骨代谢等各项指标均改变(P<0.05)。蓝光1组和蓝光2组间β-CTX、骨小梁数量和骨小梁分离度差异均有统计学意义(P<0.05)。结论:蓝光可在大鼠骨质疏松早期抑制成骨和影响钙磷代谢,促进维甲酸诱导骨质疏松的进程,提示骨质疏松患者在日常生活中需要减少蓝光暴露。

Objective:To explore the effects of blue light on bone metabolism indexes and bone microstructure of osteoporosis model induced by retinoic acid in rats.Methods:SD rats of 9 months old were randomly divided into normal group,model group,and blue light group group 1 and group 2,with 6 rats in each group.The rats in the blue light group and the model control group were fed with retinoic acid 100 mg/kg everyday for 14 days,and the normal control group was fed with distilled water of the same volume for 14 days.After 14 days,all rats recovered to normal drinking water and food.The normal control group and the model control group were exposed to daylight lamp,and blue light group 1 and group 2 were irradiated with blue light(460 nm)mode for 14 days and 21 days respectively after retinoic acid modeling.The total exposure time of fluorescent lamp irradiation was 35 days without blue light irradiation.Blood sample was collected from the orbit of all rats 35 days later,the levels of serum calcium,phosphorus,alkaline phosphatase(ALP),β-bonded degradation products(β-CTX)and amino terminal peptide of procollagen type 1(P1NP)were measured.After the animals were killed with CO 2 anesthesia,the bone mineral density,trabecular number,trabecular thickness,and trabecular separation of femur were measured by microCT.Results:Compared to the normal group,there were significant differences in calcium,phosphorus,ALP,β-CTX,and P1NP levels,and bone mineral density and microstructure in the model group(P<0.01).It showed that the model was successful.Compared to the model group,the body weight,blood level of calcium,phosphorus,ALP,β-CTX,P1NP,trabecular number,trabecular thickness,trabecular separation degree in blue light group 1 were significantly changed(P<0.05),but there was no statistical difference in bone mineral density index between the two groups.There were significant differences in body weight,bone mineral density,bone microstructure and metabolism between the blue light group 2 and the model group(P<0.05).There were significant differences inβ-CTX,trabecular number and separation between the blue light group 1 and blue light group 2(P<0.05).Conclusions:Blue light with 460 nm could promote the development of osteoporosis model induced by retinoic acid through early inhibition of osteogenesis and affecting calcium and phosphorus metabolism,which suggests that osteoporosis patients may need to reduce the exposure to blue light environment in their daily life.