Börje Haraldsson

Understanding the Kinetics of Peritoneal Transport

In this article we describe the characteristics of peritoneal barrier exchange in terms of a three-pore model of membrane permselectivity. The peritoneal membrane is thus simulated to have a large number of small pores of radius 40–55 A, a small number of large pores of radius 200–300 A, and an abundance of transcellular pores of radius 4–5 A. According to this model, solutes 30000) seemed to be absorbed from the peritoneal cavity exclusively via non-size-selective lymphatic drainage. Applying the three-pore model to literature peritoneal equilibration test (PET) data, solute mass transfer area coefficients (PS) appeared to be higher during the first 30 mins of dwell time than subsequently. Reductions in solute PS-values with dwell time are discussed in terms of a progressively increasing impact of interstitial “unstirred layers” on small solute permeation over the course of the cycle.