Responses of renal function to elevated intravesical pressure

This experimental study was designed to investigate the responses of renal function to elevated intravesical pressure. Ten male New Zealand type rabbits were used. A supravesical ureterocutaneous urinary diversion was performed in all rabbits to disconnect bladder and kidneys and to ensure a free urine flow. Two parameters of renal function were measured simultaneously: urine output by simple collection and glomerular filtration rate (GFR) by total plasma clearance of 51Cr-EDTA. Measurements were performed initially with the bladder empty and then with intravesical pressure 60 cm H2O. A significant decrease in urine output and in GFR was observed in all rabbits when the bladder was overdistended. Urine output returned to the initial levels after relief of the increased intravesical pressure. The results suggest that for these responses a vesicorenal reflex activated by the elevated intravesical pressure is responsible.