Hydronephrotic Alterations in Calyceal and Renal Pelvic Pacemaker Function of thein vitroPyeloureteral System

Abstract

There are regional variations of the amplitude, frequency and waveform of spontaneous contractions within the isolated renal pelvis and calyx of the multicalyceal pyeloureter of the pig. The contractility of these structures was studied in normal and hydronephrotic preparations. Tissues were obtained from normal and chronically obstructed animals. In 20 normal preparations, the contractile frequency of the renal pelvis was 4.9 ± 2.1 contractions/min, while that of the calyx was 9.5 ± 2.2 (mean ± SD). The recorded amplitude was 0.95 ± 0.92 and 0.45 ± 0.61 g, respectively. The waveform of the calyceal contractility approximated the sinusoid demonstrating a slow rise and fall in tension, while the waveform of renal pelvic smooth muscle demonstrated a faster increase in tension. Obstruction and hydronephrosis produced a minimal alteration in the frequency and amplitude of the calyceal structures, 9.1 ± 2.2 contractions/min and 0.71 ± 0.49 g, respectively. Hydronephrotic renal pelves demonstrated a significant increase in the frequency of spontaneous contractility 8.0 ± 4.2 contractions/min with no change in the mean amplitude of contraction 0.88 ± 0.90 g. These data suggest that obstruction alters the frequency of isolated renal pelvic contraction so that they approximate the frequency of isolated calyceal contractions.

Verapamil Inhibits the Pelvic Pressure Increase Corresponding to Flow Perfusion in the Porcine Percutaneous Renal Puncture Model

“…The normal porcine baseline renal pelvic pressure is 5-15 mm Hg, which is similar to the pelvic pressure of the humans [1]. An increase in the renal pelvic pressure tends to occur during endoluminal saline irrigation, which is familiar in endoscopy of the upper urinary tract such as percutaneous nephrolithotomy (PCNL) and ureterorenoscopy [2,3,4].…”