Klement B J, Spooner B S
Division of Biology, Kansas State University, Manhattan 66506-4901, USA.
Trans Kans Acad Sci. 1992;95(1-2):39-44.
Long term exposure to a reduced gravitational environment has a deleterious effect on bone. The developmental events which occur prior to initial bone deposition will provide insight into the regulation of mature bone physiology. We have characterized a system in which the events preceding bone formation take place in an isolated in vitro organ culture environment. We show that cultured pre-metatarsal tissue parallels development of pre-metatarsal tissue in the embryo. Both undergo mesenchyme differentiation and morphogenesis to form a cartilage rod, which resembles the future bone, followed by terminal chondrocyte differentiation in a definite morphogenetic pattern. These sequential steps occur prior to osteoblast maturation and bone matrix deposition in the developing organism. Alkaline phosphatase (ALP) activity is a distinctive enzymatic marker for mineralizing tissues. We have measured this activity throughout pre-metatarsal development and show (a) where in the tissue it is predominantly found, and (b) that this is indeed the mineralizing isoform of the enzyme.
长期暴露于低重力环境会对骨骼产生有害影响。在初始骨沉积之前发生的发育事件将有助于深入了解成熟骨生理学的调节机制。我们已经描述了一个系统，在这个系统中，骨形成之前的事件发生在一个孤立的体外器官培养环境中。我们发现，培养的前跖骨组织与胚胎中前跖骨组织的发育过程相似。两者都经历间充质分化和形态发生，形成一根类似于未来骨骼的软骨棒，随后终末软骨细胞以特定的形态发生模式分化。这些连续步骤发生在发育中的生物体成骨细胞成熟和骨基质沉积之前。碱性磷酸酶（ALP）活性是矿化组织的一种独特酶标志物。我们在整个前跖骨发育过程中测量了这种活性，并表明（a）该活性主要存在于组织的哪个部位，以及（b）这确实是该酶的矿化同工型。
