CAJ | 학술논문

目的：研究模拟失重尾部悬吊雌性大鼠模型松质骨骨密度(bonemineraldensity，BMD)、骨小梁结构、骨组织形态、骨代谢生化指标及力学性能的改变，为女性航天员飞行后骨量变化及航天医学提供一定的理论支持。方法3个月龄雌性SD大鼠20只，随机数表法分为两组，尾部悬吊4周组和空白对照组，每组10只。连续饲养4周，定期记录大鼠活动、饮食、排便、体重、有无脱毛、有无死亡或尾部脱落等一般情况。到期处死大鼠，双能X线吸收法( dual-energy X-ray absorption，DEXA )测定L4椎体、股骨踝部骨密度，Micro-CT 进行骨小梁分析，改良丽春红染色法观察骨组织形态，ELISA法检测血清骨代谢生化标志物，并行生物力学检测。结果建模4周后，2组大鼠活动、饮食、排便均正常，体重增加量两组差异无统计学意义( P＞0.05)，2组均无脱毛、死亡或尾部脱落现象。悬吊组大鼠L4椎体、股骨髁部BMD均较对照组小，分别较对照组下降29%、30%( P＜0.05)。悬吊组L4椎体、股骨髁部的骨体积分数( bone volume/total volume， BV/TV )、表面积体积比( bone surface/bone volume，BS/BV )、骨小梁厚度( trabecular thickness，Tb.Th )、骨小梁数目( trabecular number，Tb.N )分别较对照组小，L4椎体各指标较对照组分别下降40%、15%、30%、33%( P＜0.05)，股骨髁部各指标较对照组分别下降21%、25%、50%、19%( P＜0.05)；骨小梁间隙( trabecular separation，Tb.Sp )悬吊组较对照组大，且L4椎体、股骨髁部较对照组分别增加92%、33%( P＜0.05)。腰椎松质骨ROI骨小梁三维重建发现，悬吊组大鼠腰椎椎体内骨小梁密集程度、骨小梁实质的体积、粗细程度及连续性均低于空白对照组，呈明显的“蜂窝样”改变，出现明显的骨质疏松和骨小梁三维结构破坏。50X 显微镜下也观察到悬吊组大鼠椎体骨质疏松样改变明显，骨小梁不连续、变细、间隙增大明显。悬吊组大鼠血清骨碱性磷酸酶( human bone alkaline phosphatase，BALP )、抗酒石酸酸性磷酸酶( tartrate resistant acid phosphatase，TRAP )含量均较空白对照组高，为空白对照组的4.5和3.1倍( P＜0.05)。悬吊组大鼠的腰椎最大压缩载荷、最大压缩应力、股骨的最大抗弯曲载荷均较对照组小，且较对照组分别下降了36%、33%、34%(P＜0.05)。结论尾部悬吊雌性大鼠4周后出现严重的骨密度下降、骨小梁三维结构破坏、骨组织形态破坏、骨代谢失平衡、椎体及股骨生物力学显著下降，形成了明显的骨质疏松，理论上增加了骨折的风险。对女性航天员骨量丢失及骨折的风险应得到充分地认识。目的：研究模擬失重尾部懸弔雌性大鼠模型鬆質骨骨密度(bonemineraldensity，BMD)、骨小樑結構、骨組織形態、骨代謝生化指標及力學性能的改變，為女性航天員飛行後骨量變化及航天醫學提供一定的理論支持。方法3箇月齡雌性SD大鼠20隻，隨機數錶法分為兩組，尾部懸弔4週組和空白對照組，每組10隻。連續飼養4週，定期記錄大鼠活動、飲食、排便、體重、有無脫毛、有無死亡或尾部脫落等一般情況。到期處死大鼠，雙能X線吸收法( dual-energy X-ray absorption，DEXA )測定L4椎體、股骨踝部骨密度，Micro-CT 進行骨小樑分析，改良麗春紅染色法觀察骨組織形態，ELISA法檢測血清骨代謝生化標誌物，併行生物力學檢測。結果建模4週後，2組大鼠活動、飲食、排便均正常，體重增加量兩組差異無統計學意義( P＞0.05)，2組均無脫毛、死亡或尾部脫落現象。懸弔組大鼠L4椎體、股骨髁部BMD均較對照組小，分彆較對照組下降29%、30%( P＜0.05)。懸弔組L4椎體、股骨髁部的骨體積分數( bone volume/total volume， BV/TV )、錶麵積體積比( bone surface/bone volume，BS/BV )、骨小樑厚度( trabecular thickness，Tb.Th )、骨小樑數目( trabecular number，Tb.N )分彆較對照組小，L4椎體各指標較對照組分彆下降40%、15%、30%、33%( P＜0.05)，股骨髁部各指標較對照組分彆下降21%、25%、50%、19%( P＜0.05)；骨小樑間隙( trabecular separation，Tb.Sp )懸弔組較對照組大，且L4椎體、股骨髁部較對照組分彆增加92%、33%( P＜0.05)。腰椎鬆質骨ROI骨小樑三維重建髮現，懸弔組大鼠腰椎椎體內骨小樑密集程度、骨小樑實質的體積、粗細程度及連續性均低于空白對照組，呈明顯的“蜂窩樣”改變，齣現明顯的骨質疏鬆和骨小樑三維結構破壞。50X 顯微鏡下也觀察到懸弔組大鼠椎體骨質疏鬆樣改變明顯，骨小樑不連續、變細、間隙增大明顯。懸弔組大鼠血清骨堿性燐痠酶( human bone alkaline phosphatase，BALP )、抗酒石痠痠性燐痠酶( tartrate resistant acid phosphatase，TRAP )含量均較空白對照組高，為空白對照組的4.5和3.1倍( P＜0.05)。懸弔組大鼠的腰椎最大壓縮載荷、最大壓縮應力、股骨的最大抗彎麯載荷均較對照組小，且較對照組分彆下降瞭36%、33%、34%(P＜0.05)。結論尾部懸弔雌性大鼠4週後齣現嚴重的骨密度下降、骨小樑三維結構破壞、骨組織形態破壞、骨代謝失平衡、椎體及股骨生物力學顯著下降，形成瞭明顯的骨質疏鬆，理論上增加瞭骨摺的風險。對女性航天員骨量丟失及骨摺的風險應得到充分地認識。
목적：연구모의실중미부현조자성대서모형송질골골밀도(bonemineraldensity，BMD)、골소량결구、골조직형태、골대사생화지표급역학성능적개변，위녀성항천원비행후골량변화급항천의학제공일정적이론지지。방법3개월령자성SD대서20지，수궤수표법분위량조，미부현조4주조화공백대조조，매조10지。련속사양4주，정기기록대서활동、음식、배편、체중、유무탈모、유무사망혹미부탈락등일반정황。도기처사대서，쌍능X선흡수법( dual-energy X-ray absorption，DEXA )측정L4추체、고골과부골밀도，Micro-CT 진행골소량분석，개량려춘홍염색법관찰골조직형태，ELISA법검측혈청골대사생화표지물，병행생물역학검측。결과건모4주후，2조대서활동、음식、배편균정상，체중증가량량조차이무통계학의의( P＞0.05)，2조균무탈모、사망혹미부탈락현상。현조조대서L4추체、고골과부BMD균교대조조소，분별교대조조하강29%、30%( P＜0.05)。현조조L4추체、고골과부적골체적분수( bone volume/total volume， BV/TV )、표면적체적비( bone surface/bone volume，BS/BV )、골소량후도( trabecular thickness，Tb.Th )、골소량수목( trabecular number，Tb.N )분별교대조조소，L4추체각지표교대조조분별하강40%、15%、30%、33%( P＜0.05)，고골과부각지표교대조조분별하강21%、25%、50%、19%( P＜0.05)；골소량간극( trabecular separation，Tb.Sp )현조조교대조조대，차L4추체、고골과부교대조조분별증가92%、33%( P＜0.05)。요추송질골ROI골소량삼유중건발현，현조조대서요추추체내골소량밀집정도、골소량실질적체적、조세정도급련속성균저우공백대조조，정명현적“봉와양”개변，출현명현적골질소송화골소량삼유결구파배。50X 현미경하야관찰도현조조대서추체골질소송양개변명현，골소량불련속、변세、간극증대명현。현조조대서혈청골감성린산매( human bone alkaline phosphatase，BALP )、항주석산산성린산매( tartrate resistant acid phosphatase，TRAP )함량균교공백대조조고，위공백대조조적4.5화3.1배( P＜0.05)。현조조대서적요추최대압축재하、최대압축응력、고골적최대항만곡재하균교대조조소，차교대조조분별하강료36%、33%、34%(P＜0.05)。결론미부현조자성대서4주후출현엄중적골밀도하강、골소량삼유결구파배、골조직형태파배、골대사실평형、추체급고골생물역학현저하강，형성료명현적골질소송，이론상증가료골절적풍험。대녀성항천원골량주실급골절적풍험응득도충분지인식。
Objective To study the changes of bone mineral density ( BMD ) of cancellous bone, trabecular bone structure, bone tissue morphology, bone metabolic biochemical markers and mechanical properties in tail-suspended female rats under simulated weightlessness, so as to provide certain theoretical support for the research on bone mass changes in female astronauts after the lfight and aerospace medicine.Methods Twenty 3-month-old female Sprague-Dawley ( SD ) rats were randomly divided into 2 groups. The tails of the rats in group A (n=10 ) were suspended for 4 weeks, and the other rates were taken as blank control group (n=10 ). All the rates were continuously fed for 4 weeks, and their general conditions were recorded, including activities, eating and drinking,defecation, weight, unhairing or not, death and tail falling off. All the rats were sacrificed at predetermined time points. The BMD of the L4 vertebral body and femoral condyle was evaluated by dual-energy X-ray absorption ( DEXA ). Micro computed tomography ( Micro-CT ) was applied to analyze the trabecular bone. Bone tissue slice staining was conducted by using ponceau. Serum bone metabolic biochemical markers were detected by Enzyme-linked immunosorbent assay ( ELISA ), and biochemical properties were investigated.Results At 4 weeks after the establishment of osteoporosis models, the activities, eating and drinking and defecation of the rats in group A were normal, and the differences in weight gain were not statistically significant between the 2 groups (P>0.05 ). No unhairing, death or tail falling off was noticed in either group. When compared with that in blank control group, the BMD of the L4 vertebral body and femoral condyle in group A was reduced by 29% and 30% (P<0.05 ). The bone volume / total volume ( BV/TV ), bone surface/bone volume ( BS/BV ), trabecular thickness ( Tb.Th ) and trabecular number ( Tb.N ) of the L4 vertebral body in group A was reduced by 40%, 15%, 30% and 33% when compared with that in blank control group (P<0.05 ). The BV/TV, BS/BV, Tb.Th and Tb.N of the femoral condyle in group A was reduced by 21%, 25%, 50% and 19% when compared with that in blank control group (P<0.05 ). The trabecular separation ( Tb.Sp ) of the L4 vertebral body and femoral condyle in group A was increased by 92% and 33% respectively (P<0.05 ) when compared with that in blank control group (P<0.05 ). The 3-dimensional ( 3 D ) reconstruction of the trabecular bone in region of interest ( ROI ) of lumbar cancellous bone showed group A was not as good as blank control group in the intensity, real volume, size and continuity of the trabecular bone in the lumbar vertebral body. Honeycomb-like structure was detected and obvious osteoporosis and 3D structural damage were noticed. The osteoporotic bone changes and incontinuity, diminution and enlarged space of the trabecular bone were observed in group A under the microscope ( 50X ). The human bone alkaline phosphatase ( BALP ) and tartrate resistant acid phosphatase ( TRAP ) in group A was 4.5 and 3.1 times higher than that in blank control group (P<0.05 ). The maximal compressive load and maximal compressive stress of the lumbar vertebral body and the maximal lfexural load of the femur in group A were decreased by 36%, 33% and 34% when compared with that of blank control group (P<0.05 ).Conclusions The significant decrease of the BMD of cancellous bone, 3 D structural damage of the trabecular bone, morphological destruction of bone tissues, bone metabolism imbalance and obvious reduction of mechanical strength of the vertebral body and femur are detected in the tail-suspended rats at 4 weeks after the establishment of osteoporosis models. The visible signs of osteoporosis are observed, and the risk of fracture is increased theoretically. A full understanding of bone mass loss and fracture risk in female astronauts should be developed.