Nephrectomy and peritoneal dialysis eliminates circulating renin and controls uraemia in the rat

OBJECTIVE: The aim of the present study was to develop a rat model for in vivo studies of the local effects of the renin-angiotensin system (RAS) following elimination of circulating renin.

METHODS: Sprague Dawley rats were bilaterally nephrectomised and had a peritoneal dialysis catheter implanted. The rats were maintained on dialysis continuously for 48 hours, using Dianeal PD4 3.86% glucose dialysis solution. The peritoneal catheter and an automated system for dialysate exchange were made in our laboratory. A sham nephrectomised control group of rats was also dialysed.

RESULTS: Nephrectomised and sham-operated rats remained active and in good general condition during peritoneal dialysis. At 48 hours, in nephrectomised, dialysed rats, peritoneal urea clearance was 4.14+/-0.52 ml/hour, plasma urea was 40.0+/-7.7 mmol/L, plasma creatinine was 0.423+/- 0.070 mmol/L and plasma renin was below the limit of detection.

CONCLUSIONS: In conclusion, it was possible to sustain bilaterally-nephrectomised rats on continuous peritoneal dialysis for 48 hours, pending elimination of renin from the circulation. The nephrectomised dialysed rat model should be useful for investigation of the physiological effects of the circulating versus the local RAS.