Peritoneal Changes after Exposure to Sterile Solutions by Catheter

Abstract

Most current animal models that are used to study effects of long-term peritoneal exposure to dialysis solutions use an indwelling catheter for daily injections. It was hypothesized that the presence of a foreign body in the peritoneal cavity (PC) might alter the inflammatory response to the solutions and that the response would depend on exposure duration. For addressing these, long-term injections were carried out for 2 to 8 wk in 90 Sprague-Dawley rats: 40 via a subcutaneous port connected to a silicone catheter tunneled to the PC, 40 via direct needle injection, and 10 noninjected, age-control rats. Daily volumes were 30 to 40 ml of filter-sterilized, bicarbonate-buffered solutions that contained 4% dextrose. After 2, 4, 6, and 8 wk, anesthetized rats underwent transport experiments with a chamber affixed to the abdominal wall to determine mass transfer coefficients of mannitol (MTC mannitol ) and albumin (MTC BSA ), osmotic filtration flux (J osm ), and hydrostatic pressure-driven flux. After the rats were killed, tissues were collected for measurement of peritoneal thickness, vascular density, and immunohistochemical staining. ANOVA demonstrated significant (P Ͻ 0.01) differences in thickness, vessel density, MTC mannitol , and MTC BSA among the groups at the various time intervals and in overall means. Differences among the groups were less pronounced for hydrostatic pressure-driven flux and J osm . Vessel density, MTC mannitol , MTC BSA , and J osm were dependent on injection duration (P Ͻ 0.01). There were marked differences between the needle injection and catheter injection groups at various intervals in the expression of three cytokines. It is concluded that the histologic and functional response depends on the duration of injection with animals that are exposed for as little as 2 wk demonstrating alterations. These findings confirm the hypothesis that the presence of a PC catheter increases inflammatory response to sterile solutions as evidenced by the structural and functional changes in the peritoneal barrier. 18: 229418: -230218: , 200718: . doi: 10.1681 Exposure of the peritoneum to sterile solutions that contain glucose results in changes in cellular characteristics, histology, and barrier function. Long-term peritoneal dialysis (PD) without evidence of peritonitis alters the phenotypic appearance of the human peritoneum in 8 to 12 mo. 1 Biopsy studies of longterm (Ͼ3 yr) PD patients have demonstrated marked thickening over time of the subcompact zone, a region between the mesothelial cells and their basement membrane, with corresponding changes in the underlying microvasculature. 2 Exposure of patients to glucose-based dialysis solutions resulted in significant functional changes in transperitoneal transport in a 2-yr study of patients who were treated with automated PD. 3 Studies in animal models parallel these changes and have demonstrated benefit of solutions that are thought to be more biocompatible. 4 -6 Studies in our laboratory using an animal model with a subcutaneous inj...

Rapamycin inhibits epithelial‐to‐mesenchymal transition of peritoneal mesothelium cells through regulation of Rho GTPases

“…infiltration compared with the N group, which was slightly different from Flessner's study [47]. Meanwhile, the HG group showed a pronounced thicker peritoneum and more inflammatory response than the NS group.…”

“…There are two basic types of PD models in nonuremic rats: one that are treated with daily intraperitoneal injection of PD solution [22,25,45] and another that are infused with PD solution after implantation of biomaterials like silicone or Dacrone [9,44,46]. It has been demonstrated that intraperitoneal implantation of silicone catheter may induce inflammatory response and important mesothelial changes on peritoneum [47][48][49]. In our in vivo result, the NS group inserted with a silicone catheter showed a mildly increased peritoneum thickness but no obvious inflammatory cell proliferation and The group NS showed a mildly higher protein and mRNA expression of a-SMA and TGF-b1 than the group NC; The group L-RAPA and group H-RAPA both significantly decreased the protein and mRNA expression of a-SMA and TGF-b1, which were significantly increased in the group HG.…”

Severe ileus after colonoscopy in a patient on peritoneal dialysis

“…Patients on PD have many predisposing factors for chronic intraperitoneal inflammatory conditions; therefore, these patients likely have increased risk for adhesion compared with the general population. Repeated exposures to bio-incompatible PD solutions are related to the development of intraperitoneal inflammation [12], and the PD catheter itself is also independently associated with the disruption of peritoneal membrane integrity, which contributes to intraperitoneal adhesion [13]. However, anatomical adhesion band in this case was not confirmed.…”

Peritoneal Dialysis Catheter Increases Leukocyte Recruitment in the Mouse Parietal Peritoneum Microcirculation and Causes Fibrosis

“…In rat models of PD, the catheter implant appeared to make a large contribution to the damage of the parietal peritoneum. Changes in peritoneal structure, histology, and function were more profound when PD fluids were instilled through a catheter implant compared with intraperitoneal (IP) injections with a needle (12,13). These studies emphasize that the effects of dialysis solutions on peritoneal pathology, function, and inflammatory responses in animal models cannot be examined without careful differentiation of the effects of the PD fluid versus the peritoneal catheter.…”