AJP - Regulatory, Integrative and Comparative Physiology, Vol 241, Issue 5 412-R418, Copyright © 1981 by American Physiological Society
Multiple-coupled pacemaker system in renal pelvis of the unicalyceal kidney
C. E. Constantinou and O. Yamaguchi
The characteristics of spontaneous contractility in the renal pelvis were
examined in the unicalyceal kidney of the rabbit. In vitro isometric
studies were done on whole as well as renal pelvic segments dissected
longitudinally and radially. The results show that the contractile
frequency of isolated segments was highest in the proximal region (4.188
+/- 0.162 min-1) and decreased distally to (2.178 +/- 0.330 min-1). There
was no significant frequency gradient in the circumferential direction. A
modulation of wave form (waxing and waning phenomena) was observed in both
the proximal and middle regions of the pelvis. Based on these results, a
simulation of the renal pelvic activity was made by using a chain of
coupled linear oscillators. At high values of coupling a pacemaker
contraction of the renal pelvis was reproduced by the coupled oscillator
model. The modulation of wave form was observed when the coupling of the
circumferential direction was weak. These results are discussed in the
context of the hierarchically organized multiple-coupled pacemaker system,
which characterizes an integrative activity of the unicalyceal renal
pelvis.
