In vivo recording of renal pelvic pacemaker potential.

Attempts have been successful to obtain electromyographic (EMG) recording of discharges of action potentials at the proximal end of canine renal pelvis in vivo by application of the Gil-Vernet procedure of extended pyelolithotomy. The discharges recorded in vivo from the proximal end of the renal pelvis in adult mongrel dogs showed EMG patterns characterized by a slow-rising positive waveform with virtually constant discharge intervals, irrespective of micturitional condition: normosthenuric or diuretic. The EMG pattern had striking resemblance to that obtained for the pacemaker of pyeloureteral peristalsis at the pelvicalyceal border in vitro. Potentials recorded at the lower pelvis, pyeloureteral junction and ureter in vivo showed increased frequencies of discharge during diuresis, compared to normal condition, the discharge intervals being always integral multiples of the interval of potentials at the proximal end of the renal pelvis.