目的: 探究275 nm与310 nm紫外线对去卵巢骨质疏松大鼠骨代谢的影响。方法: 24只3月龄雌性SD(Sprague-Dawley)大鼠随机分为对照组、假手术组、275 nm紫外线照射组与310 nm紫外线照射组,每组6只。275 nm紫外线照射组与310 nm紫外线照射组施行双侧卵巢摘除手术,假手术组行卵巢旁少许脂肪组织摘除,对照组未行手术处理。术后24周测定大鼠颈椎、腰椎、股骨近心端、股骨中段和股骨远心端骨密度。骨质疏松大鼠模型制备成功后,分别给予骨质疏松大鼠275 nm、310 nm紫外线照射,辐照强度均为15 μW/cm ²,每日照射90 min,每周照射7 d,共16周,每周定时剃去大鼠背部毛发(面积为6 cm×8 cm)。照射16周后,测定大鼠颈椎、腰椎、股骨近心端、股骨中段和股骨远心端骨密度。处死动物后,取血并分离血清,测定血清25(OH)D、Ⅰ型原胶原N-端前肽(procollagen type Ⅰ N-peptide, PINP)与骨钙素(osteocalcin, OC)的含量。结果: 双侧卵巢摘除术24周后,与对照组[(238.78±26.74) mg/cm³]相比,275 nm紫外线照射组[(193.34±13.28) mg/cm³]和310 nm紫外线照射组[(191.19±18.48) mg/cm³]大鼠骨密度均显著下降(P=0.002,P=0.001); 假手术组[(227.20±14.32) mg/cm³]与对照组相比差异无统计学意义。对骨质疏松大鼠进行紫外线照射16周后,275 nm紫外线照射组大鼠全身平均骨密度显著增加[(193.34±13.28) mg/cm³ vs. (221.68±25.52) mg/cm ³,P=0.005], 310 nm紫外线照射组大鼠全身平均骨密度显著增加[(191.19±18.48) mg/cm³ vs. (267.48±20.54) mg/cm ³,P<0.001]。275 nm紫外线照射组大鼠腰椎、股骨近心端、股骨中段和股骨远心端的骨密度平均水平均增加; 310 nm紫外线照射组大鼠颈椎、腰椎、股骨近心端、股骨中段和股骨远心端5个部位的骨密度平均水平均显著提高。275 nm紫外线照射组大鼠血清25(OH)D及OC含量均显著高于对照组[(46.78±5.59) μg/L vs. (21.32±6.65) μg/L,P=0.002;(2.05±0.53) U/L vs. (1.32±0.07) U/L,P=0.022];310 nm紫外线照射组大鼠血清25(OH)D[(58.05±12.74) μg/L]、PINP[(176.16±24.18) U/L]和OC[(2.04±0.53) U/L]水平也均显著高于对照组(P<0.001,P=0.015,P=0.005)。假手术组与对照组相比,大鼠血清25(OH)D、PINP及OC含量差异无统计学意义。结论: 275 nm和310 nm紫外线均能促进大鼠维生素D合成,显著改善骨质疏松大鼠骨质状况,310 nm紫外线照射对于骨质状况的改善作用更强。

Objective: To investigate the effect of 275 nm and 310 nm ultraviolet irradiation on ovariectomized rats’ bone metabolism. Methods: Twenty four 3-month-old female Sprague-Dawley (SD) rat were randomly divided into control group, sham operated group, 275 nm ultraviolet (UV) irradiation group and 310 nm UV irradiation group. Each group contained 6 rats. The rats in the two irradiation groups were treated with bilateral ovariectomy. The rats in sham operated group received sham operation (They were given the same back incision and a bit of par-ovarian fat were removed). Control group received no disposition. About 24 weeks after operation, all the rats received detailed bone mineral density (BMD) detection again. Detection regions include cervical vertebra, lumbar vertebra, proximal femur, mid femur and distal femur. Next, osteopenia rats in 275 nm irradiation group were UV irradiated 275 nm with fixed illumination intensity (15 μW/cm²) everyday for 16 weeks. The osteopenia rats in 310 nm irradiation group were UV irradiated 310 nm with fixed illumination intensity (15 μW/cm ²) everyday for 16 weeks. The backs of the rats were shaved regularly as irradiation area (6 cm×8 cm). After 16-week irradiation, all the rats’ BMD of cervical vertebra, lumbar vertebra, proximal femur, mid femur and distal femur were measured. At the end of the trial, all the rats’ blood specimens were obtained and serum 25(OH)D, procollagen type Ⅰ N-peptide (PINP) and osteocalcin (OC) were measured. Results: Compared with control group [(238.78±26.74) mg/cm³], the BMD of the whole body were significantly lower in 275 nm [(193.34±13.28) mg/cm³] and 310 nm [(191.19±18.48) mg/cm³] irradiation groups (P=0.002,P=0.001). There were no significant difference between sham operated group [(227.20±14.32) mg/cm³] and control group. After 16-week ultraviolet irradiation, the BMD of the whole body were significantly increased in 275 nm [(193.34±13.28) mg/cm³ vs. (221.68±25.52) mg/cm ³,P=0.005] and 310 nm groups [(191.19±18.48) mg/cm³ vs. (267.48±20.54) mg/cm ³,P<0.001] after corresponding irradiation. The BMD of the four body regions (lumbar vertebra, proximal femur, mid femur and distal femur) had significantly increased after irradiation in 275 nm irradiation group. For 310 nm irradiation group, the BMD in cervical vertebra, lumbar vertebra, proximal femur, mid femur and distal femur also had increased significantly after 310 nm ultraviolet irradiation. The concentration of serum 25(OH)D and OC was higher in 275 nm irradiation group than in control group [(46.78±5.59) μg/L vs. (21.32±6.65) μg/L, P=0.002;(2.05±0.53) U/L vs. (1.32±0.07) U/L,P=0.022]. Compared with the control, the concentration of serum 25(OH)D [(58.05±12.74) μg/L], OC [(2.04±0.53) U/L] and PINP [(176.16±24.18) U/L] was significantly higher (P<0.001, P=0.015, P=0.005) in 310 nm irradiation group. However, there were no significantly difference between sham operated group and the control. Conclusion: Both 275 nm and 310 nm ultraviolet could improve rats’ vitamin D synthesis. Both 275 nm and 310 nm ultraviolet could improve osteopenia rats’ bone condition. The irradiation of 310 nm might be more effective on bone condition improvement.