Sanders Kenton M, Ward Sean M, Koh Sang Don
Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada.
Physiol Rev. 2014 Jul;94(3):859-907. doi: 10.1152/physrev.00037.2013.
Smooth muscles are complex tissues containing a variety of cells in addition to muscle cells. Interstitial cells of mesenchymal origin interact with and form electrical connectivity with smooth muscle cells in many organs, and these cells provide important regulatory functions. For example, in the gastrointestinal tract, interstitial cells of Cajal (ICC) and PDGFRα(+) cells have been described, in detail, and represent distinct classes of cells with unique ultrastructure, molecular phenotypes, and functions. Smooth muscle cells are electrically coupled to ICC and PDGFRα(+) cells, forming an integrated unit called the SIP syncytium. SIP cells express a variety of receptors and ion channels, and conductance changes in any type of SIP cell affect the excitability and responses of the syncytium. SIP cells are known to provide pacemaker activity, propagation pathways for slow waves, transduction of inputs from motor neurons, and mechanosensitivity. Loss of interstitial cells has been associated with motor disorders of the gut. Interstitial cells are also found in a variety of other smooth muscles; however, in most cases, the physiological and pathophysiological roles for these cells have not been clearly defined. This review describes structural, functional, and molecular features of interstitial cells and discusses their contributions in determining the behaviors of smooth muscle tissues.
平滑肌是一种复杂的组织，除肌肉细胞外还包含多种细胞。间充质来源的间质细胞与许多器官中的平滑肌细胞相互作用并形成电连接，这些细胞具有重要的调节功能。例如，在胃肠道中，已详细描述了 Cajal 间质细胞（ICC）和 PDGFRα(+) 细胞，它们代表具有独特超微结构、分子表型和功能的不同细胞类别。平滑肌细胞与 ICC 和 PDGFRα(+) 细胞电耦合，形成一个称为 SIP 合体的整合单元。SIP 细胞表达多种受体和离子通道，任何类型的 SIP 细胞中的电导变化都会影响合体的兴奋性和反应。已知 SIP 细胞可提供起搏活动、慢波传播途径、运动神经元输入的转导以及机械敏感性。间质细胞的缺失与肠道运动障碍有关。在多种其他平滑肌中也发现了间质细胞；然而，在大多数情况下，这些细胞的生理和病理生理作用尚未明确界定。本综述描述了间质细胞的结构、功能和分子特征，并讨论了它们在决定平滑肌组织行为方面的作用。
