The source and possible significance of hyaluronan in the peritoneal cavity.

The levels of hyaluronan (HA) were determined in dialysate from patients receiving CAPD. The levels found after the four hour dwell were 0.162 +/- 0.08 micrograms/ml (N = 16) in non-infected fluid and 1.69 +/- 1.12 (N = 5) during peritonitis, P < 0.0025. Similarly concentrations in overnight (8 to 10 hours) dwell dialysate were 0.384 +/- 0.22 micrograms/ml (N = 13) when uninfected and 3.17 +/- 2.28 (N = 8) during peritonitis, P < 0.0002. Following de novo catheter insertion the initial peritoneal washout yielded HA levels of 0.0032 +/- 0.0018 micrograms/ml (N = 7). In vitro human peritoneal cells synthesized HA, 90% of which was secreted into the culture medium (CM). By dissociative gel permeation chromatography on Sephacryl 1000 there were no significant differences in the molecular size of HA extracted from (a) non-infected fluid, (b) infected fluid and (c), mesothelial cell culture medium. These results indicate that the process of CAPD results in an increase in HA levels in the peritoneal cavity. During episodes of peritonitis these functions are further augmented. The likely source of HA in the dialysate is the peritoneal mesothelial cells. This response may be an initial event in wound repair.