The simultaneous recording of the rhythmic contraction and electrical activity of the renal previs--a new in vitro method.

A new in vitro method which enables the simultaneous recording of the electromyogram from various regions of the renal pelvis and the pressure changes associated with those electrical activities is described in an experiment on canine kidney. At the proximal end of the renal pelvis, the interval of the electromyogram was constant and pelvic pressure changes showed rhythmic activity, while the discharge interval of the proximal end was the same as the pressure interval. However, the discharge intervals of both the pelvic center and the pelviureteric junction were found to be multiples of that of the proximal end of the pelvis.