不同强度运动和雌激素联合作用对去卵巢大鼠骨骼影响的骨形态计量学研究

目的：探讨不同强度运动及运动与雌激素联合作用对去卵巢大鼠不同部位骨骼的影响及机制。方法：72只3月龄雌性SD大鼠去卵巢分成：正常对照组（SHAM）、骨质疏松对照组（OVX）、雌激素对照组（OVX＋ES）、3个单纯运动组（低强度运动组（OVX＋EX1）、中等强度运动组（OVX＋EX2）、大强度运动组（OVX＋EX3））以及3个运动与雌激素联合组（低强度运动加雌激素组（OVX＋EX1＋ES）、中等强度运动加雌激素组（OVX＋EX2＋ES），大强度运动加雌激素组（OVX＋EX3＋ES）），用骨形态计量学方法，研究8周的1h／day，5days／week低强度（8m／min）、中等强度（18m／min）和大强度（28m／min）跑台运动对大鼠胫骨近端（PTM）及第四腰椎（L4）松质骨骨量的影响。结果：1）OVX组骨量由于骨代谢增加比SHAM组降低（P〈0．05），而补充雌激素后，骨丢失减少。2）单纯运动对骨量的影响：与OVX组比较，OVX＋EX1组和OVX＋EX2组胫骨的骨吸收减少（P〈0．05）、骨形成增加、骨量增加（EX2比EX1增加更多），OVX＋EX3与OVX组差异无显著性意义。3种强度的单纯运动均能对腰椎产生有益的作用。3）对于运动和雌激素的联合作用：在胫骨，3个联合组均比雌激素对照组和各自强度的单纯运动组骨量增多（P〈0．05）。在腰椎，无此协同作用。结论：去卵巢大鼠骨骼对于运动的反应与该部位是否是载荷直接作用部位和去卵巢大鼠是否补充雌激素有关。

Histomorphometric Study on the Effects of Combination of Different Intensity Exercise and Estrogen on Bone Mass in Ovariectomized Rats

This paper discussed the effect and mechanism of individual or combined different intensity treadmill exercise and estrogen on different bone in ovareictomized rats.Seventh two female Sprague Dawly rats aged at three months were divided into following groups:SHAM,OVX and OVX ES(ovariectomy with estrogen administration),three groups of individual exercise of different intensity:OVX EX1,OVX EX2 and OVX EX3,three combined groups of estrogen and exercise:OVX EX1 ES,OVX EX2 ES,and OVX EX3 ES.Exercise consisted of treadmill running for 1 h/day,5days/week,at the velocity of 8m/min(EX1),18 m/min(EX2) and 28m/min (EX3) with the duration of eight weeks.Histomorphometric measurement on the cancellous bone in proximal tibia metaphysis(PTM) and the 4~(th) lumbar vertebral body(L4) were investigated.The result showed that ovariectomy led to cancellous bone loss significantly(P<0.05) in PTM and L4 by increasing bone formation and resorption,whereas it can be diminished by estrogen administration.The effect of individual exercise on bone mass:in PTM,the response of skeleton to exercise was related to exercises intensity and the bone mass of EX1 and EX2 were higher than that of in OVX(P<0.05)(EX2 better than EX1) by decreasing bone resorption and increasing bone formation,but that of EX3 was not so.In L4,the response of skeleton to exercises was the global increase in bone mass in all of the three individual exercise groups than that of OVX.The effects of combination of exercise and estrogen on bone mass.In PTM,there was a much better collaborate reaction of skeleton on exercises in three combined groups than that in the groups of estrogen administration alone and exercise alone.In L4,there was no collaborate effect in combination groups.It concluded that the responses of skeleton to exercise related to that whether or not the bone was the site loaded directly and whether or not estrogen administration of ovariectomized rats were performed.