title: Effect of hydrogen peroxide on rabbit urinary bladder citrate synthase activity in the presence and absence of a grape suspension.
abstract: OBJECTIVE
  The etiology of obstructive bladder dysfunction includes free radical damage to mitochondria. Feeding rabbits a standardized grape suspension protects the ability of the bladder to contract and empty in part by preventing mitochondrial damage, thus maintaining smooth muscle and mucosal metabolism. The objective of the current study is to determine the direct effect of this grape suspension on the response of mitochondria to the oxidative effects of hydrogen peroxide.
  
  
  METHODS
  Six male rabbits were anesthetized with sodium pentobarbital and the bladders excised. Four full thickness strips were obtained for contractile studies and the balance separated into smooth muscle and mucosa compartments by blunt dissection. The effect of hydrogen peroxide on the contractile response to field stimulation was quantitated. Each tissue was homogenized and the effects of increasing concentrations of hydrogen peroxide in the presence and absence of grape suspension on citrate synthase activity was determined.
  
  
  RESULTS
  Citrate synthase activity was significantly higher in the mucosa than in the muscle. The grape suspension had no effect on control citrate synthase activity. However, the grape suspension provided significant protection of both smooth muscle and mucosal citrate synthase activity.
  
  
  CONCLUSIONS
  These studies support the conclusion that the grape suspension provides direct protection of mitochondrial function.
authors.affiliation: Albany College of Pharmacy and Health Sciences, Albany, New York 12208, USA.
authors.forename: Vijay
authors.initials: V
authors.lastname: Venugopal
authors.forename: Robert E
authors.initials: RE
authors.lastname: Leggett
authors.forename: Catherine
authors.initials: C
authors.lastname: Schuler
authors.forename: Robert M
authors.initials: RM
authors.lastname: Levin
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002950:Citrate (si)-Synthase / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000009:adverse effects / Q000494:pharmacology*; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D009092:Mucous Membrane / Q000187:drug effects / Q000201:enzymology; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000201:enzymology; D011817:Rabbits; D001743:Urinary Bladder / Q000187:drug effects* / Q000201:enzymology; D001748:Urinary Bladder Neck Obstruction / Q000201:enzymology; D027843:Vitis
chemical_list: D000975:Antioxidants; D006861:Hydrogen Peroxide; D002950:Citrate (si)-Synthase