Chronic alteration of subperitoneal tissue and peritoneal transport

Based on previous work, we hypothesized that the alterations in tissue hyaluronan concentration ([HA]) brought about by chronic treatment of the peritoneum would result in corresponding changes in solute and water transport. To address that hypothesis, we carried out daily intraperitoneal (i.p.) injections for 2 months in 200-300 g rats of 30-40 mL of a sterile solution via peritoneal catheter tunneled to a subcutaneous port in the neck. Solutions used were: 4% N-acetylglucosamine (NAG), 4% mannitol (M), 4% glucose (G), and control group (C). After 2 months, each animal underwent transport studies, using plastic chambers affixed to the parietal peritoneum of the abdominal wall, to determine: small-solute mass, osmotic filtration, and albumin flux in response to 450-500 mOsm/kg. After each animal was humanely killed, the tissue below the chamber was removed and analyzed for [HA]. A 50% enhancement in [HA] in tissue was seen in NAG-treated animals as compared with animals in the other groups. Results for small-solute transport (one-way ANOVA, p > 0.6) and osmotic filtration (one-way ANOVA, p > 0.2) both demonstrated no significant differences among groups. The albumin flux (mean +/- standard error of the mean) in the control group (C) was significantly higher (0.36 +/- 0.03 microL/min/cm2) than in the three treatment groups, but no difference was seen among the treatment groups (NAG: 0.25 +/- 0.03 microL/min/cm2; M: 0.26 +/- 0.03 microL/min/cm2; G: 0.29 +/- 0.03 microL/min/cm2; one-way ANOVA, p = 0.064). We conclude that increasing [HA] by 50% in parietal peritoneal tissue does not bring about major changes in transperitoneal transport.