Chronic administration of iron dextran into the peritoneal cavity of rats

Objective: To determine the influence of chronic iron dextran administrations into the peritoneal cavity of rats on function and anatomy of the peritoneal membrane, as well as on erythropoiesis and serum iron. Design: Prospective randomized animal study. Setting: Animal laboratory. Animals: 36 Sprague-Dawley rats. Interventions: The rats were divided into three groups (n = 12). The animals were given standard 1.5% Dianeal (control group) or 1.5% Dianeal containing iron dextran in a concentration of 2 mg/L [low-dose group (LDG)] or 10 mg/L [high-dose group (HDG)]. Main outcome measures: On the 8th day, at 3 months, and at 6 months a 2-hour peritoneal equilibration test (PET) and blood tests including hematocrit, serum iron, and total iron-binding capacity (TIBC) were done. After the final PET at 6 months, the peritoneal membrane was evaluated by gross inspection and by light microscopy. Results: Hematocrit and serum iron levels increased only in the HDG and LDG. Peritoneal transport of small solutes decreased significantly in the HDG compared to baseline. All cases of the HDG group revealed peritoneal adhesions and fibrosis around the peritoneal catheter as well as massive iron deposits on the peritoneum. Similar but less pronounced changes were found in the LDG. Conclusions: These findings suggest an efficient absorption of iron from the peritoneal cavity of rats, however, dialysate iron dextran concentrations of 2 mg/L or greater are toxic to the peritoneal membrane. Therefore, future studies should be performed to determine the minimal effective and nontoxic iron dextran concentrations for intraperitoneal administration.