Renal blood flow and function at elevated ureteric pressure. An experimental study in the pig.

The unilateral ureteric pressure was successively elevated in five piglets. Bilateral studies of renal blood flow and related parameters (cardiac output, renal vascular resistance, mean arterial and mean venous blood pressures) revealed no significant changes. At a unilateral ureteric pressure of 10 mm Hg, there was a temporary decrease in the renal vascular resistance in both kidneys concomitatnt with an increase in renal blood flow. Glomerular and tubular function decreased successively as the unilateral ureteric pressure was increased. At a retrograde pressure of 75 mm Hg, some renal function was still preserved, probably due to pyelolymphatic backflow.