An Experimental Study of the Lower End of the Ureter and Ureterovesical Junction in Dogs1

SUMMARY Peristalsis in the lower end of the ureter was recorded in thirteen dogs by means of small polyethylene T‐tubes and changes were observed during bladder filling and emptying before and after resection of the mucosal flap valve. The following results were obtained:– 1. Peristalsis increased in amplitude and frequency as the bladder pressure rose. 2. Excessively high bladder pressure caused ureteric distension with fast peristalsis over a raised base‐line pressure. This was followed by fatigue. 3. Complete resection of the mucosal flap valve did not cause reflux if ureteric peristalsis was normal. However, reflux did occur if peristalsis was abnormal or abolished. 4. D‐tubocurarine in high doses did not abolish peristalsis.