Influence of prednisolone on glucose and uric acid transport across peritoneal membrane in vitro.

Prednisolone and other glucocorticosteroids are used by some peritoneal dialysis patients because of underlying diseases such as peritonitis. Although corticosteroids are potent inhibitors of various processes during inflammation, their influence on the transport properties of peritoneum is little known. Our study investigated the influence of prednisolone (0.001 g/dL) on glucose (1.8 g/dL) and uric acid (0.02 g/dL) transfer across isolated parietal peritoneum taken from the anterior abdominal wall of white Hyplus 59 rabbits and placed inside a modified Ussing-type chamber. Values for transfer from the interstitial (I) to the mesothelial (M) side of membrane (I-->M) and in the opposite direction (M-->I) were calculated using the mathematical model of mass transport and are expressed as a coefficient of diffusive permeability [P (in centimeters per second)]. Four separate series of experiments were done. In the first and second series, we respectively examined glucose transport under control conditions (for 120 minutes) and then before (15-60 minutes) and after (75-120 minutes) introduction of prednisolone on the M side of the membrane. In the third and fourth series, similar studies of uric acid transfer were done. In the control (first and third) series, the stability of bidirectional transport for solute of interest was observed. The values of P +/- standard error of the mean (all x0.0001) for I-->M and M-->I transfer of glucose were, respectively, 2.489 +/- 0.329 cm/s and 2.259 +/- 0.493 cm/s. In the case of uric acid, the transport values were lower and amounted 1.936 +/- 0.324 cm/s and 1.895 +/- 0.596 cm/s for I-->M and M-->I respectively. Application of prednisolone on the M side of membrane lowered bidirectional transfer of glucose across peritoneal membrane by a mean of 73% (p < 0.02) and transport of uric acid by a mean of 19% (p < 0.003). These results show that, in vitro, prednisolone lowers glucose and uric acid transport across the peritoneal membrane, modifying the transfer dynamics of glucose to a greater extent. These observations may have clinical importance, especially in patients with disorders of peritoneal permeability, diabetes, and hyperuricemia.