title: Effect of glycine on recovery of bladder smooth muscle contractility after acute urinary retention in rats.
abstract: OBJECTIVE
  To investigate the effects of glycine on the recovery of bladder smooth muscle contractility after acute urinary retention.
  
  
  METHODS
  Bladder overdistension was induced in Sprague-Dawley rats by an infusion of saline (twice the threshold volume), maintained for 2 h. From 15 min before emptying of the bladder until 2 h after, saline or glycine solution was infused i.v. At 30 min, 2 h and 1 week after bladder emptying, samples of bladder tissue were taken for muscle strip study, malondialdehyde (MDA) assay, ATP assay, Western blotting for apoptosis-related molecules (Bcl-2, Bax, Caspase-3), and histological analysis including terminal deoxynucleotidyl transferase-mediated nick-end labelling staining. The results were compared among normal control, saline-treated and glycine-treated rats.
  
  
  RESULTS
  In the glycine-treated group, muscle strip contractile responses induced by electrical-field stimulation and carbachol were both significantly greater at 1 week after bladder emptying than in the saline-treated group. The results of the ATP assay appeared to correspond with those of the muscle strip study. The saline-treated group had significantly higher MDA levels at 30 min after bladder emptying than the glycine-treated group. At 2 h after bladder emptying, there was significantly more apoptosis and greater leukocyte infiltration in the saline-treated group than in the glycine-treated group. While pro-apoptotic Bax and caspase-3 were down-regulated, Bcl-2 was up-regulated in the glycine-treated group.
  
  
  CONCLUSIONS
  Glycine infusions might improve the contractile responses of bladder smooth muscle after acute urinary retention by reducing oxidative damage and apoptosis.
authors.affiliation: Department of Urology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sung K
authors.initials: SK
authors.lastname: Hong
authors.forename: Hwancheol
authors.initials: H
authors.lastname: Son
authors.forename: Soo W
authors.initials: SW
authors.lastname: Kim
authors.forename: Seung-June
authors.initials: SJ
authors.lastname: Oh
authors.forename: Hwang
authors.initials: H
authors.lastname: Choi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D005260:Female; D005998:Glycine / Q000494:pharmacology*; D018684:Glycine Agents / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D001743:Urinary Bladder / Q000187:drug effects*; D016055:Urinary Retention / Q000503:physiopathology*
chemical_list: D018684:Glycine Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D005998:Glycine