Evidence for a humoral factor in unilaterally nephrectomized dogs stimulating renal growth in isolated canine kidneys

Totally isolated canine kidneys were perfused at 37 degrees C. for 240 minutes with whole blood from dogs that had undergone a sham operation or a unilateral nephrectomy 24 hours previously. Renal blood flow, glomerular filtration rate, serum sodium, and serum osmolality were not significantly different in the experimental and control preparations. Nucleic acid synthesis as measured by 3H-adenine incorporation was 75 percent higher (p less than 0.01) in the kidneys perfused with blood from the neprectomized dogs. This result supports the theory that a blood-borne factor stimulates nucleic acid synthesis and initiates compensatory renal growth.