Epithelial Transport Physiology

The general theme of Epithelial Transport Physiology is epithelial transport of molecules and ions, which includes the regulation of these mechanisms either directly, through secondary messengers, or via nuclear commands. Biologic transport of ions and, or, molecules across epithelial bio-membranes are mediated by proteins or protein-based molecules. Over the past forty to forty-five years, the primary structures of many of these proteins have been elucidated. One of the universalities that has emerged during this investigative process is the commonality of function amongst epithelial transporters up and down the phylogenetic tree of animals. The central subject of Epithelial Transport Physiology is to provide a comprehensive, contemporary review of epithelial transport and the responsible transporter proteins, while elucidating the wide spectrum of new methods examining epithelial transporters such as patch clamping, reconstitution, molecular biology and molecular physiology that are now available for the application to epithelial plasma membrane systems. The scope of this book was preempted and precipitated by the pioneering studies of Ussing and co-workers. The first phase of the phenomenological description of the cell as a black box has been followed by studies of cellular mechanisms, the interplay of the different transport components, and the mechanisms of regulation which will be covered in the individual chapters. For the individual epithelia transport schemes that have been proposed, I think it is appropriate to take pause and search for elements common to several epithelia. This aspect triggered the common theme idea for this book, and in fact the various chapters emphasize that the functional transporter components, expressed in the various epithelia, are not infinite in number, but they occur in epithelia which are separated in evolution by several hundred million years.