Impaired gut barrier in experimental chronic uremic rats

The intestinal permeability in chronic uremic rats on a high- and a low-protein diet was measured with a mixture of differently sized polyethylene glycols (PEG 400 and PEG 1000). The permeability was assessed by the 24-hour urinary recovery of PEG molecules (range 326-1,162 Da) administrated orally or intravenously. The urinary recovery after oral load, when corrected with the recovery after intravenous administration, was significantly enhanced in the uremic rats. A decreased urinary recovery was observed in the groups on the low-protein feed diet. There was also decreased selectivity towards larger PEGs in uremia. The results thus suggest that (i) the intestinal permeability is increased in chronic uremic rats, and (ii) the intestinal permeability is influenced by a low-protein diet.