Rat models in peritoneal dialysis

Background. It is widely accepted that the currently used dialysis solution s are not biocompatible with the peritoneal membrane. Therefore, animal stu dies have been performed to study different aspects of peritoneal dialysis. However, representative models mimicking the human situation are not yet a vailable. Methods. The effect of a single injection of peritoneal dialysis (PD) fluid on the cellular composition was studied. Thereafter, the effect of a singl e injection of PD fluid on bacterial clearing was tested over time. Finally , an in vivo rat model was established to study the effects of long-term ex posure to PD fluid on the peritoneal membrane and the local host defence (p eritoneal cells). Results. In the rat model, long-term daily exposure is possible. The 'drop- out' after 9-10 weeks on the most commonly used PD fluid Dianeal 3.86%, how ever, is similar to 50% due to omental wrapping. In the remaining study gro up, large differences were observed (as compared with controls), especially with respect to morphological parameters. Conclusions. The rat peritoneal continuous exposure model seems to have pot ential for intervention studies, since it uses no additions, no antibiotics and no omentomectomy, and gives continuous long-term exposure to PD fluid. However, problems still remain: 'drop-out' is quite often seen and this no n-uraemic exposure model does not totally mimic the situation present in co ntinuous ambulatory PD patients.