Effects of physicochemical factors on the growth of mandibular condyles in vitro
Effects of physicochemical factors on the growth of mandibular condyles in vitro
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DOI：
10.1007/bf00334332
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发表时间：
1994-06
影响因子：
4.2
通讯作者：
A. M. Garcia;A. Black;Martha L. Gray
中科院分区：
文献类型：
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作者：
A. M. Garcia;A. Black;Martha L. Gray
已知软骨生长和重塑受组织的生物化学和机械环境的影响。以前的研究表明，与机械负荷相关的化学因素，如渗透压和pH值，诱导软骨代谢的变化。使用新生大鼠下颌骨髁突培养系统，本文报道的工作的目的是确定（1）生长如何受到机械负荷的影响;（2）组织内渗透压或pH值的变化是否会引起软骨的代谢变化，然后通过改变生长行为来反映。使用高分子量（MW）不带电的大分子聚乙烯吡咯烷酮（PVP）和Ficoll（假定无法穿透组织基质）来检查渗透负荷对组织生长的影响;渗透压高达100 kPa的浓度导致生长和基质积累的剂量依赖性抑制。棉子糖（它可以穿透基质，但不能穿透细胞）对渗透压高达87 kPa的生长没有显着影响，这表明压缩诱导的组织内渗透压变化不太可能提供细胞感知和响应机械压缩的信号。相比之下，培养基pH值的变化导致生长行为的剂量依赖性变化。具体而言，轻微的碱性（酸性）大大增强（减少）的增长和基质积累; pH值的敏感性表明，组织内pH值可以提供一种机制，细胞感知当地的糖胺聚糖浓度和机械压缩。这些数据也是重要的，虽然以前的研究人员已经表明，渗透力和pH值影响生物合成率在短期的文化，目前的研究表明，由此产生的变化，生物合成导致改变生长速度。
Cartilage growth and remodeling are known to be influenced by the biochemical and mechanical environment of the tissue. Previous investigators have shown that chemical factors that are relevant to mechanical loading, such as osmotic pressure and pH, induce changes in cartilage metabolismin vitro. Using a neonatal rat mandibular condyle culture system, the objectives of the work reported here were to determine (1) how the growth is influenced by osmotically applied mechanical loads; and (2) whether changes in intratissue osmotic pressure or pH cause metabolic changes in the cartilage which are then reflected by altered growth behavior. High molecular weight (MW) uncharged macromolecules polyvinylpyrrolidone (PVP) and Ficoll (presumed unable to penetrate the tissue matrix) were used to examine the effect of osmotic loading on tissue growth; concentrations corresponding to osmotic pressures of up to 100 kPa resulted in a dose-dependent depression in growth and matrix accumulation. Raffinose (which can penetrate the matrix but not the cells) had no significant effect on growth for osmotic pressures of up to 87 kPa, suggesting that compression-induced changes in intratissue osmotic pressure are unlikely to provide a signal by which cells sense and respond to mechanical compression. By contrast, changes in medium pH resulted in dose-dependent changes in growth behavior. Specifically, slight alkalinity (acidity) greatly enhanced (diminished) growth and matrix accumulation; the sensitivity to pH suggests that intratissue pH could provide a mechanism for cells to sense local glycosaminoglycan concentration and mechanical compression. These data are also significant in that, while previous investigators have shown that osmotic forces and pH affect biosynthetic rates in short-term culture, the present studies indicate that resultant changes in biosynthesis lead to altered growth rates.