Premium
The Peritoneal Microcirculation in Peritoneal Dialysis
Author(s) -
RIPPE BENGT,
ROSENGREN BERTINGE,
VENTUROLI DANIELE
Publication year - 2001
Publication title -
microcirculation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.793
H-Index - 83
eISSN - 1549-8719
pISSN - 1073-9688
DOI - 10.1111/j.1549-8719.2001.tb00178.x
Subject(s) - peritoneal cavity , peritoneal dialysis , microcirculation , chemistry , peritoneum , biophysics , capillary action , membrane , chromatography , materials science , medicine , surgery , biochemistry , biology , composite material
This paper deals with the peritoneal microcirculation and with peritoneal exchange occurring in peritoneal dialysis (PD). The capillary wall is a major barrier to solute and water exchange across the peritoneal membrane. There is a bimodal size‐selectivity of solute transport between blood and the peritoneal cavity, through pores of radius ∼40–50 Å as well as through a very low number of large pores of radius ∼250 Å. Furthermore, during glucose‐induced osmosis during PD, nearly 40% of the total osmotic water flow occurs through molecular water channels, termed “aquaporin‐1.” This causes an inequality between 1−σ and the sieving coefficient for small solutes, which is a key feature of the “threepore model” of peritoneal transport. The peritoneal interstitium, coupled in series with the capillary walls, markedly modifies small‐solute transport and makes large‐solute transport asymmetric. Thus, although severely restricted in the blood‐to‐peritoneal direction, the absorption of large solutes from the peritoneal cavity occurs at a high clearance rate (∼1 mL/min), largely independent of molecular radius. True absorption of macromolecules to the blood via lymphatics, however, seems to be occurring at a rate of ∼0.2 mL/min. Several controversial issues regarding transcapillary and transperitoneal exchange mechanisms are discussed in this paper.