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.

Response of urinary sodium excretion to elevated intravesical pressure.

This experimental study was designed to investigate the possibility of an interaction between elevated intravesical pressure and urinary sodium excretion. Fourteen male New Zealand rabbits were used. After performing a ureterocutaneous diversion, urinary sodium excretion was measured in two situations: with the bladder empty and with the bladder overdistended and an intravesical pressure of 60 cm H2O. There was a significant decrease in urinary sodium excretion at an elevated intravesical pressure. The urinary sodium excretion returned to normal after relief of the pressure. The results suggest the existence of a neurogenic pathway activated by the elevated intravesical pressure.

[Effect of acute distension of the bladder on blood flow and the resistance of the peripheral vessels]. / Le retentissement de la distension aiguë de la vessie sur le débit sanguin et les résistances des vaisseaux périphériques.

The effects of acute, rapid distention of the urinary bladder on the arterial pressure, blood flow and peripheral resistances were studied on dogs and an attempt was made to elucidate the mechanisms of cardiovascular responses observed. In 15 dogs with intact nervous system the arterial blood pressure and blood flow of the femoral, brachial and renal arteries were recorded and the vascular resistances were calculated during an increase of the intra-bladder pressure. Acute distention of the bladder, in the dog, increases arterial blood pressure by 10,25%, the vascular resistance of the femoral and renal vascular bed increases while that of the brachial artery is slightly reduced.