上部尿路の活動電位の研究

Abstract

The purpose of this investigation was to determine if the ureter segments above and below the site of transection in some way restore their activities after making a communication between them using an artificial ureter in order to make the flow of urine possible.Fifty-five mongrel dogs were used in the present study. Each ureter was sectioned transversely at the central part and reconstructed with a vinyl T-shaped catheter. In this preparation, the upper and lower segments of the ureter were completely separated each other and thus the flow of urine occurred via vinyl catheter secured between them.The action potentials and pressure of the upper and lower segments of the ureters were measured according to Kubo et al, and compared with those of the ureters prior to surgery.The results obtained are as follows: 1) In all dogs studied, the ureters before surgery showed normal peristalsis on the myogram recordings and pressure waves; 2) of sectioned ureters, 17 out of 35 segments below the site of section lost peristalsis (48.6%), anti-peristalsis occurred in 11 ureters (31.4%) and normal peristalsis in 7 ureters (20.0%). In all cases showing anti-peristalsis no pressure waves were seen. In the ureters showing normal peristalsis the pressure waves were normal in all but one. No change was seen in the segment of the ureter above the site of transection; 3) When the upper and lower segments of the sectioned ureter were communicated through a vinyl catheter, normal peristalsis occurred in the lower segment of 33 ureters and anti-peristalsis was seen in 2 ureters. The pressure waves were seen in all ureters having normal peristalsis. However, in the ureters having anti-peristalsis, small pressure waves were preceded by action potentials. All upper segments of the ureter showed normal peristalsis and pressure waves; 4) When the flow through the communication secure dbetween the upper and lower ureters was interrupted by clamping, neither peristalsis nor pressure waves were seen in the lower segment of 8 ureters. Of 10 ureters showing anti-peristalsis, 9 had no tracing of pressure waves. In one ureter, the appearance of the pressure waves was preceded by action potentials. In 17 ureters showing normal peristalsis, 8 had normal tracings, while 9 had no tracings. All upper segments of the ureter showed normal peristalsis but the resting pressure was markedly elevated. In 4 cases, the pressure waves disappeared as the resting pressure increased; 5) When the urine through the communication between the upper and lower segments of the ureter was allowed to pass, the normal peristalsis was restored in the lower segments of 34 ureters with a concomitant appearance of normal pressure waves. Only one ureter showed anti-peristalsis but no pressure waves.The results of the present study show that the segment of the ureter below the site of transection can restore its activity if the urine is allowed to pass through an appropriate communication secured between the upper and lower segments of the ureter. These findings are compatible with the concept that the urine flow per se acts like a stimulus to the ureteral activity.