Mosekilde L, Thomsen J S, Orhii P B, McCarter R J, Mejia W, Kalu D N
Department of Cell Biology, Institute of Anatomy, University of Aarhus, Denmark.
Bone. 1999 Feb;24(2):71-80. doi: 10.1016/s8756-3282(98)00169-0.
The aim of the study was to assess the effect of growth hormone (GH), voluntary exercise (Ex), and the combination of GH and Ex on bone strength, mass, and dimensions in aged, intact female rats. In addition, the effect of food restriction (FR) was studied. Fourteen-month-old virgin F-344 rats were divided into 6 groups with 13 animals in each: (1) baseline (BSL); (2) control + solvent vehicle (CTRL); (3) GH 2.5 mg/kg/day (GH); (4) exercise, voluntary: 0.6-0.7 km/day (Ex); (5) GH treatment and voluntary exercise (GH + Ex); and (6) FR. Group 1 was killed at the beginning of the study and served as baseline. All the other groups were killed after 18 weeks' treatment. The effects of aging and treatment regimes were measured at four different skeletal sites: lumbar vertebrae, femoral cortical bone, femoral neck, and the distal femoral metaphysis. Aging in itself induced a decline in vertebral body strength and ash density. At the appendicular skeletal sites, bone mass and strength were unchanged or increased. Treatment with GH alone induced a significant increase in the biomechanical parameters at the vertebral body and the femoral diaphysis, but not at the femoral neck or the distal femoral metaphysis. Voluntary exercise on its own increased load values significantly over CTRL at the vertebral body site, but not at any of the appendicular skeletal sites. The combination of GH and voluntary exercise resulted in an additive effect at the vertebral site and at the femoral diaphysis, and a synergistic (potentiating) effect at the two femoral metaphyses. FR, on the other hand, had a negative effect on cortical bone area and strength at the femoral diaphysis, but no significant effect on the other sites tested. We conclude that GH treatment and voluntary exercise both have skeletal anabolic effects; however, these effects are exerted to differing degrees at different sites. Importantly, when dosed together, GH and Ex have either an additive or synergistic anabolic effect on all sites (axial and appendicular).
本研究的目的是评估生长激素（GH）、自主运动（Ex）以及GH与Ex联合应用对老年未切除卵巢雌性大鼠骨强度、骨量和骨尺寸的影响。此外，还研究了食物限制（FR）的影响。将14月龄的处女F-344大鼠分为6组，每组13只：（1）基线组（BSL）；（2）对照组+溶剂载体（CTRL）；（3）GH 2.5 mg/kg/天（GH）；（4）自主运动：0.6 - 0.7 km/天（Ex）；（5）GH治疗与自主运动（GH + Ex）；（6）食物限制组（FR）。第1组在研究开始时处死，作为基线。所有其他组在治疗18周后处死。在四个不同的骨骼部位测量衰老和治疗方案的影响：腰椎、股骨皮质骨、股骨颈和股骨远端干骺端。衰老本身导致椎体强度和灰密度下降。在四肢骨骼部位，骨量和强度未改变或增加。单独使用GH治疗可使椎体和股骨干的生物力学参数显著增加，但股骨颈和股骨远端干骺端未增加。自主运动本身在椎体部位使负荷值比对照组显著增加，但在任何四肢骨骼部位均未增加。GH与自主运动联合应用在椎体部位和股骨干产生相加效应，在两个股骨干骺端产生协同（增强）效应。另一方面，食物限制对股骨干的皮质骨面积和强度有负面影响，但对其他测试部位无显著影响。我们得出结论，GH治疗和自主运动都具有骨骼合成代谢作用；然而，这些作用在不同部位的程度不同。重要的是，当一起给药时，GH和Ex对所有部位（轴向和四肢）都有相加或协同的合成代谢作用。
