[Pacemakers of the upper urinary tract using power spectral analysis of spontaneous activity].

Spontaneous activity of isolated smooth muscle strips of the upper urinary tract has been analysed by time series analysis. Frequency components of spontaneous contractions of the human urinary tract have been determined quantitatively by means of power spectral analysis. This method allows to characterise exact frequency components of rhythmicity in various parts of the urinary tract and accordingly helps to localise the site of various pacemakers. The results indicate tentatively the existence of two different pacemakers located in the wall of calix and pelvis. Furthermore, it is assumed that these pacemakers complement each other both cooperatively and by additive functioning, as though in shifts (reverberation), to stimulate urine transport through the pyeloureter.