title: Pacemakers in the upper urinary tract.
abstract: BACKGROUND
  Pacemakers in upper urinary tract (UUT) are still under study.
  
  
  OBJECTIVE
  We reviewed the role of some cells that seem to be involved in the propulsion of urinary bolus from UUT to the bladder.
  
  
  METHODS
  We focuses on evaluating studies on the mechanisms by which the UUT propels urine to the bladder via pacemaker cells.
  
  
  RESULTS
  Electric active pacemaker cells generate pyeloureteric autorhythmicity driving adjacent smooth muscle cells (SMCs); it emphasizes the role of the interstitial cells of Cajal-like cells (ICC-LCs) localized in the UUT. Interstitial cells of Cajal (ICCs) are now thought to cooperate in conducting and amplifying pacemaker activity in the UUT. These cells produce electrical slow-wave potentials and determine the propagation of peristaltic activity. Identification of ICC-LCs is facilitated by use of c-kit antibodies. Contraction waves arising from the UUT and the propagation of these waves may require the direct involvement of ICC-LCs, as c-kit immunoreactivity appears developmentally at the same time as coordinated unidirectional peristaltic contraction. ICC-LCs observed in the UUT have morphological features similar to those of c-kitpositive ICCs in the gastrointestinal tract. In addition to gastrointestinal motility, ICCs may also play a significant role in the propagation, coordination, and modulation of ureteropelvic peristalsis.
  
  
  CONCLUSIONS
  Alterations in ICC-LCs are closely associated with a variety of motility disorders and many congenital urological diseases of the UUT such as primary obstructive megaureter, congenital ureteropelvic junction obstruction, and vesicoureteral reflux.
  
  
  CONCLUSIONS
  These observations open the way for further investigations of this cell type.
authors.affiliation: Unit of Urology, University of Messina, Messina, Italy.
authors.forename: Antonina
authors.initials: A
authors.lastname: Di Benedetto
authors.forename: Salvatore
authors.initials: S
authors.lastname: Arena
authors.forename: Piero Antonio
authors.initials: PA
authors.lastname: Nicotina
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mucciardi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Galì
authors.forename: Carlo
authors.initials: C
authors.lastname: Magno
mesh_terms: D001683:Biological Clocks / Q000502:physiology*; D055724:Electrophysiological Phenomena / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000502:physiology; D009130:Muscle, Smooth / Q000502:physiology; D014513:Ureter / Q000002:abnormalities; D014517:Ureteral Obstruction / Q000175:diagnosis / Q000503:physiopathology; D001743:Urinary Bladder / Q000294:innervation / Q000502:physiology; D014553:Urinary Tract Physiological Phenomena; D014570:Urologic Diseases / Q000175:diagnosis / Q000503:physiopathology*; D014718:Vesico-Ureteral Reflux / Q000175:diagnosis / Q000503:physiopathology