title: Does Methylphenidate Affect Cystometric Parameters in Spontaneously Hypertensive Rats?
abstract: OBJECTIVE
  Methylphenidate (MPH) is one of the most commonly prescribed psychostimulants for attention deficit hyperactivity disorder (ADHD). However, there is limited research on its effects on lower urinary tract function. This study investigated changes in cystometric parameters after intragastric administration of MPH in conscious spontaneously hypertensive rats (SHRs), an animal model of ADHD.
  
  
  METHODS
  Fourteen- to 16-week-old male SHRs (n=10), weighing between 280 and 315 g, were used. Three micturition cycles were recorded before administering MPH. One hour after each intragastric MPH injection, three cycles of cystometrogram were obtained in the awake condition. Various cystometric parameters were evaluated, including basal pressure (BP), maximal pressure (MP), threshold pressure (TP), bladder capacity (BC), micturition volume (MV), micturition interval (MI), and residual volume (RV). The data were analyzed using paired Student t-tests.
  
  
  RESULTS
  Five SHRs were each administered a dose of 3-mg/kg MPH, and the other five received a dose of 6-mg/kg MPH. BP and MP increased significantly in the rats that received the 3-mg/kg MPH injection, but not in those that received the 6-mg/kg injection. BC, MV, and MI significantly increased in the rats that received the 6-mg/kg MPH injection, but not in those that received the 3-mg/kg injection. There were no significant changes in TP after either injection.
  
  
  CONCLUSIONS
  Significant increases in BC, MV, and MI after the 6-mg/kg MPH injection suggest that the peripheral and the central nervous systems may play important roles in bladder function in those receiving MPH for ADHD.
authors.affiliation: Department of Urology, Gachon University Gil Medical Center, Gachon University College of Medicine, Incheon, Korea.
authors.forename: Khae Hawn
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Urology, Hallym University Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Ha Bum
authors.initials: HB
authors.lastname: Jung
authors.affiliation: Department of Urology, Hallym University Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Don Kyoung
authors.initials: DK
authors.lastname: Choi
authors.affiliation: Department of Pharmacology, Inha University College of Medicine, Incheon, Korea.
authors.forename: Geun Ho
authors.initials: GH
authors.lastname: Park
authors.affiliation: Department of Urology, Hallym University Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Sung Tae
authors.initials: ST
authors.lastname: Cho
keywords: Attention Deficit Disorder with Hyperactivity; Methylphenidate; Rats; Urodynamics