Effect of renin, ischemia, and plasma protein loading on the isolated perfused kidney

¹ Cedars-Sinai Medical Center, Cedars of Lebanon Division, Medical Research Institute, Los Angeles, California

Normal renal function has been maintained in an isolated artificial heart-lung, whole-blood perfused rabbit kidney for periods of 2–4 hr. The isolated kidney responds to changes in perfusion pressure, changes in plasma protein concentration, and exposure to a 10-min period of ischemia, in a manner similar to that described for the kidney of the normal intact animal. Elevation of the plasma protein concentration produces a fall in the rate of urine flow, sodium excretion, and creatinine clearance, and a marked proteinuria. The administration of renin produces a marked diuresis, natriuresis, and proteinuria. This effect is also produced by the exposure of the isolated kidney to a 10-min period of ischemia, suggesting that this response may be mediated by a renin mechanism. The responses of the kidney to these two procedures differ only in that ischemia produces an increase in renal blood flow and renin produces a slight reduction in renal blood flow and a more pronounced proteinuria.

Key Words: renin and ischemia on kidney • increased plasma protein • concentration • proteinuria • epinephrine • perfusion pressure • potassium • natriuresis

Submitted on March 31, 1965