Ortoft G, Oxlund H, Andreassen T T
Department of Connective Tissue Biology, Institute of Anatomy, University of Aarhus, DK-8000 Aarhus C, Denmark.
Calcif Tissue Int. 1998 Jul;63(1):14-21. doi: 10.1007/s002239900483.
Our earlier studies have shown that growth hormone administration could not counteract decreased longitudinal growth and cortical osteopenia of rat femora induced by a glucocorticoid with depot effect. In the present study we examined the effects of glucocorticoid on vertebral bone as well as the effect of growth hormone on vertebral bone in young growing animals also given glucocorticoid injections. Five groups of female rats (3 1/2 months) were treated for 80 days as follows: (1) saline, (2) prednisolone: Delcortol 5 mg/kg/day, (3) growth hormone: 5 mg/kg/day, (4) prednisolone and growth hormone, (5) food restriction. Vertebral dimensions, histomorphometry, and mechanical competence of the vertebral bone were examined. Growth hormone administration increased body weight, vertebral height, cross-sectional area, and volume. The compressive strength of the L4-corpus cylinder was also increased due to an increase in cancellous bone volume and an increase in the area of cortical bone surrounding the vertebral body. Glucocorticoid administration decreased body weight, height, and volume of the intact vertebrae. Histological examination revealed that glucocorticoid administration decreased the area of cortical bone surrounding the vertebral body but had no effect on the cancellous bone volume. No effect of glucocorticoid administration on mechanical strength of the L4 corpus cylinder could be detected. In agreement with our findings in cortical bone, we found no effect of growth hormone on vertebral bone when given to animals also receiving glucocorticoid injections. Growth hormone increases longitudinal growth, cortical and cancellous bone mass, and mechanical competence of the vertebral body. Glucocorticoid administration decreases longitudinal growth of the vertebrae and cortical bone mass without affecting cancellous bone mass of the vertebral body. Despite this, administration of a glucocorticoid with depot effect totally inhibits the effect of growth hormone on vertebral bone.
我们早期的研究表明，给予生长激素并不能抵消具有长效作用的糖皮质激素所诱导的大鼠股骨纵向生长减缓及皮质骨减少。在本研究中，我们检测了糖皮质激素对幼龄生长动物椎骨的影响，以及生长激素对同时给予糖皮质激素注射的幼龄生长动物椎骨的影响。五组雌性大鼠（3.5个月龄）接受如下处理80天：（1）生理盐水；（2）泼尼松龙：Delcortol 5毫克/千克/天；（3）生长激素：5毫克/千克/天；（4）泼尼松龙和生长激素；（5）食物限制。检测了椎骨尺寸、组织形态计量学及椎骨的力学性能。给予生长激素可增加体重、椎骨高度、横截面积和体积。由于松质骨体积增加以及椎体周围皮质骨面积增加，L4椎体圆柱体的抗压强度也增加。给予糖皮质激素可降低完整椎骨的体重、高度和体积。组织学检查显示，给予糖皮质激素可减少椎体周围皮质骨的面积，但对松质骨体积无影响。未检测到给予糖皮质激素对L4椎体圆柱体力学强度的影响。与我们在皮质骨中的发现一致，我们发现，在同时接受糖皮质激素注射的动物中给予生长激素，对椎骨没有影响。生长激素可增加纵向生长、皮质骨和松质骨量以及椎体的力学性能。给予糖皮质激素可降低椎骨的纵向生长和皮质骨量，而不影响椎体的松质骨量。尽管如此，给予具有长效作用的糖皮质激素可完全抑制生长激素对椎骨的作用。
