Hyaluronan influence on diffusive permeability of the peritoneum in vitro

Hyaluronan (HA), an essential component of peritoneal extracellular matrix, participates in restoring peritoneal integrity and remodeling the peritoneum changed by prolonged peritoneal dialysis and repeated peritonitis episodes. The aim of the present study was to compare urea, creatinine, and uric acid transport across the peritoneal membrane in control conditions and after HA application. Experiments were undertaken using rabbit parietal peritoneum and a modified Ussing-type chamber. Values of the transfer directed from the interstitial to the mesothelial side of the membrane (I --> M) and in the opposite direction (M --> I) were expressed as coefficients of diffusive permeability P. Transperitoneal transport in control conditions (for 120 minutes) and transfer parameters before (15 - 60 minutes) and after HA application (2000 kDa, 0.04 g/dL, 75-120 minutes) were examined. In the control series, stability of bidirectional transport for urea (0.02 g/dL), creatinine (0.1 g/dL), and uric acid (0.02 g/dL) was observed. The values of P +/- standard error of the mean for I --> M and M --> I transfers were respectively 2.293 +/- 0.211 and 2.621 +/- 0.457 for urea, 1.522 +/- 0.102 and 1.865 +/- 0.244 for creatinine, and 1.936 +/- 0.324 and 2.078 +/- 0.186 for uric acid [all x 10(-4) cm/s]. Application of HA reduced bi-directional urea transport by a mean of 12%, but did not change the P for creatinine and uric acid. These results show that in vitro HA modifies the dynamics of transport for certain small solutes.