Evaluation of enhanced peritoneum permeability in methylglyoxal-treated rats as a diagnostic method for peritoneal damage.

ABSTRACT

PURPOSE: As peritoneal damage in long-term peritoneal dialysis therapy is a major problem correlated to patient prognosis, diagnosis of peritoneal damage is important. To develop a diagnostic method for peritoneal damage, we focused on hyperpermeability across the peritoneum in a pathogenic peritoneal damage condition. In this study, disposition characteristics of an intraperitoneally injected marker substance in peritoneal damaged rats were analyzed. MATERIALS AND METHODS: Peritoneal damaged rats were prepared by intraperitoneal injection of a glucose degradation product, methylglyoxal (MGO), for five or ten consecutive days. Phenolsulfonphthalein (PSP), as a marker substance, was intraperitoneally or intravenously injected into MGO-treated rats. Subsequently, the PSP disposition characteristics were pharmacokinetically analyzed. RESULTS: In both cases of 5 and 10 days treatment of MGO, absorption of PSP after intraperitoneal injection was significantly enhanced. Plasma concentration and urinary excretion of PSP in MGO-treated rats were also higher than those in saline-treated rats in the early phase. On the contrary, there was no significant difference in terms of the pharmacokinetic parameters of intravenously injected PSP in saline- or MGO-treated rats. These results indicated that intraperitoneally injected MGO primarily acts on the peritoneal membrane; therefore, the peritoneal permeability of the marker substance was enhanced. CONCLUSION: We demonstrated that pharmacokinetic analysis of peritoneum permeability might be a potent diagnostic method for peritoneal damage in experimental animals and patients receiving peritoneal dialysis.