Estrogen and "exercise" have a synergistic effect in preventing bone loss in the lumbar vertebra and femoral neck of the ovariectomized rat

被引：51

作者：

Li, CY ^{[1
]}

Jee, WSS ^{[1
]}

Chen, JL ^{[1
]}

Mo, A ^{[1
]}

Setterberg, RB ^{[1
]}

Su, M ^{[1
]}

Tian, XY ^{[1
]}

Ling, YF ^{[1
]}

Yao, W ^{[1
]}

机构：

[1] Univ Utah, Div Radiobiol, Salt Lake City, UT 84108 USA

来源：

CALCIFIED TISSUE INTERNATIONAL | 2003年 / 72卷 / 01期

关键词：

bipedal stance "exercise; estrogen; bone histomorphometry; lumbar vertebral body; femoral neck;

D O I：

10.1007/s00223-001-1086-y

中图分类号：

R5 [内科学];

学科分类号：

1002 ; 100201 ;

摘要：

This study was designed to study the individual or combined effects of estrogen and bipedal stance "exercise" on the lumbar vertebral body (LVB) and femoral neck (FN). At 6 months of age, six rats were sacrificed as baseline controls and all the others were either bilateral sham-ovariectomized or ovariectomized (OVX). Groups of OVX rats were housed in normal height cage (NC, 28 cm) or raised height cages (RC, 33 cm) and received biweekly s.c. injections of 10 mug/kg 17beta estradiol (E-2) or vehicle for 4 and 8 weeks. Histomorphometric measurements were performed on the undecalcified mid-transverse sections of the 4(th) LVB and FN. Ovariectomy alone induced cancellous bone loss by 21% and 39% in the LVB and FN. respectively intracortical porosity area of the FN increased by 108% while total bone area did not change significantly, because of the periosteal expansion following OVX. E-2 alone partially prevented cancellous bone loss in the LVB and FN and prevented increased intracortical porosity area in the FN by reducing eroded surface and activation frequency. RC alone partially prevented the decrease of cancellous bone in the LVB and FN by reducing the bone-eroded surface but increased wall width. E-2 plus RC completely preserved cancellous bone by having an additive effect on reducing eroded Surface and activation frequency. RC helped to partially prevent decreased periosteal bone formation after estrogen administration. In conclusion, apart from inducing cancellous bone loss in the LVB and FN, OVX also increased intracortical remodeling in the FN. Estrogen prevented,he overall activation of remodeling space induced by OVX. Apart from having similar effects as estrogen on remodeling space, RC induced positive bone balance within each remodeling unit. Combination treatment increased total bone mass beyond that of sham-control level by having an additive effect on lowering bone remodeling and increasing wall in both the LVB and FN.

引用

页码：42 / 49

页数：8

共 36 条

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