Electrorenogram: Recording of Electric Waves from the Canine Kidney

Abstract

Electrical activity of the renal parenchyma was studied aiming at characterizing an electrorenogram (ERG) for the normal kidney. The right kidney of 15 mongrel dogs was exposed through an oblique lumbar incision, and 3 electrodes were sutured to the renal capsule in the upper, middle and lower third of the kidney. Simultaneous transcutaneous recording of the renal electric waves was performed by applying another 3 electrodes to the skin of the loin. The effect of renal vessel clamping as well as of nephrectomy on the renal electrical activity was also tested. Electric waves were recorded from both the directly and transcutaneously applied electrodes. They each consisted of a negative followed by a positive deflection and had identical frequency and amplitude from all the electrodes, direct or transcutaneous, in the same animal. The transcutaneous waves have been validated by their similarity to the ones obtained from the directly implanted electrodes. Temporary renal vessel clamping did not affect the recorded activity except that the waves had lower frequency and amplitude than those before clamping. No electric waves were registered after nephrectomy. An ERG pattern could be identified for the normal kidney which might be deranged in various renal pathologic conditions. This study is preliminary, however, and further studies are needed on a large number of normal and pathologic kidneys.