首页> 外文期刊>American Journal of Physiology >Modeling of transcellular Ca transport in rat duodenum points to coexistence of two mechanisms of apical entry.
【24h】

Modeling of transcellular Ca transport in rat duodenum points to coexistence of two mechanisms of apical entry.

机译:大鼠十二指肠中跨细胞Ca转运的模型指出了两种心尖进入机制的共存。

获取原文
获取原文并翻译 | 示例
           

摘要

Employing realistic parameters, we have demonstrated that a relatively simple mathematical model can reproduce key features of steady-state Ca2+ transport with the assumption of two mechanisms of Ca2+ entry: a channel-like flux and a carrier-mediated transport. At low luminal [Ca2+] (1-5 mM), facilitated entry dominates and saturates with Km = 0.4 mM. At luminal [Ca2+] of tens of millimolar, apical permeability is dominated by the channel flux that in turn is regulated by cytosolic Ca2+. The model reproduces the linear relationship between maximum Ca2+ transport rate and intestinal calbindin D9K (CaBP) content. At luminal [Ca2+] > 50 mM, local sensitivity analysis shows transcellular transport to be most sensitive to variations in CaBP. At low luminal [Ca2+], transport becomes sensitive to apical entry regulation. The simulations have been run within the Virtual Cell modeling environment, yielding the time course of external Ca2+ and spatiotemporal distributions of both intracellular Ca2+ and CaBP. Coexistence of two apical entry mechanisms accords with the properties of the duodenal Ca2+ transport protein CaT1 and the epithelial Ca2+ channel ECaC.
机译:利用现实的参数,我们已经证明了一个相对简单的数学模型可以重现稳态Ca2 +传输的关键特征,并假设有两种Ca2 +进入机制:通道状通量和载体介导的传输。在低腔内[Ca2 +](1-5 mM)时,容易进入并以Km = 0.4 mM饱和。在数十毫摩尔的腔内[Ca2 +]时,顶端通透性受通道通量的支配,而通道通量又受胞质Ca2 +的调节。该模型再现了最大Ca2 +传输速率与肠道钙结合蛋白D9K(CaBP)含量之间的线性关系。当腔内[Ca2 +]> 50 mM时,局部敏感性分析表明跨细胞转运对CaBP的变化最敏感。在低腔内[Ca2 +]下,转运对根尖进入调节敏感。该仿真已在虚拟细胞建模环境中进行,得出了外部Ca2 +的时程以及细胞内Ca2 +和CaBP的时空分布。两种心尖进入机制的共存符合十二指肠Ca2 +转运蛋白CaT1和上皮Ca2 +通道ECaC的特性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号