Ultrastructural Morphology of the Peritoneum: New Findings and Speculations on Transfer of Solutes and Water during Peritoneal Dialysis

The mechanisms of water and solute transfer across exchange vessels still are one of the most important and unsolved questions of modern physiology. During the last few years, several investigators have developed a combined approach trying to correlate physiological studies with ultrastructural observations ( 1-4) .The understanding of the transfer mechanisms across the peritoneal membrane during peritoneal dialysis is an even more complicated issue. There is a need to integrate the known (as well as the unknown) about capillary physiology with the yet-unclear role of the mesothelial layer during dialysis -a situation which can be hardly called nonnal physiology. This review brings together recent findings and views of both morphology and physiology of the peritoneal dialysis system.