Effect of hypertonic dialysate and vasodilators on peritoneal dialysis clearances in the rat

A model for performing peritoneal dialysis in the rat was established which permitted the consistent measurement of dialysis clearances. The effects on urea and inulin clearances of interperitoneal vasodilators and 4.25% dextrose were compared. Isoproterenol, nitroprusside, histamine, and bradykinin, when added to 1.5% dextrose dialysate for three consecutive exchanges, all produced approximately a 20% increase in urea and inulin dialysis clearances. These increases in clearances persisted in the three subsequent exchanges when no drugs were added to the dialysate. The addition of isoproterenol, nitroprusside, or histamine to six consecutive exchanges did not produce a further increment in clearances. The use of 4.25% dextrose dialysate for three exchanges produced approximately a 50% increase in urea and inulin clearances. Clearances remained about 35% greater than control values in the subsequent three 1.5% dextrose exchanges.