title: In vitro and in vivo effects of vardenafil (a PDE-5 Inhibitor) on corpus cavernosal smooth muscle relaxation in diabetic rabbits.
abstract: BACKGROUND
  Diabetes mellitus is associated with impaired cavernosal smooth muscle relaxation (CSMR) and the development of erectile dysfunction (ED). Vardenafil, a phosphodiesterase type 5 inhibitor has been used to treat ED. The aim of this study was to assess the in vitro and in vivo effects of vardenafil on diabetic rabbit CSMR.
  
  
  METHODS
  Organ bath studies were used.
  
  
  RESULTS
  Sodium nitroprusside (SNP)- and electrical field stimulation (EFS)-induced CSMR in diabetic rabbits given the vehicle was significantly impaired when compared with controls. The in vitro addition of vardenafil significantly enhanced SNP-induced CSMR in diabetic animals given the vehicle. SNP-induced CSMR in diabetic animals given in vivo vardenafil was significantly increased when compared with the diabetic untreated group. The in vitro addition of vardenafil significantly enhanced SNP and EFS-induced CSMR in cavernosal tissue taken from diabetic animals given vardenafil in vivo.
  
  
  CONCLUSIONS
  The present findings suggest that the combination of in vitro and in vivo vardenafil enhance diabetic CSMR, reinforcing the use of vardenafil for the treatment of diabetes-induced ED.
authors.affiliation: Department of Clinical Biochemistry, Royal Free Hospital and University College Medical School, University College London, Royal Free Campus, London, UK.
authors.forename: D H W
authors.initials: DH
authors.lastname: Lau
authors.forename: F H
authors.initials: FH
authors.lastname: Mumtaz
authors.forename: D P
authors.initials: DP
authors.lastname: Mikhailidis
authors.forename: C S
authors.initials: CS
authors.lastname: Thompson
mesh_terms: D000818:Animals; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5 / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000150:complications* / Q000201:enzymology / Q000503:physiopathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D007172:Erectile Dysfunction / Q000188:drug therapy* / Q000201:enzymology / Q000209:etiology / Q000503:physiopathology; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000201:enzymology / Q000503:physiopathology; D009599:Nitroprusside / Q000494:pharmacology; D010413:Penis / Q000187:drug effects* / Q000201:enzymology / Q000503:physiopathology; D058986:Phosphodiesterase 5 Inhibitors; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology*; D011817:Rabbits; D013450:Sulfones / Q000494:pharmacology; D014227:Triazines / Q000494:pharmacology; D000069058:Vardenafil Dihydrochloride; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D007093:Imidazoles; D058986:Phosphodiesterase 5 Inhibitors; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D013450:Sulfones; D014227:Triazines; D014665:Vasodilator Agents; D009599:Nitroprusside; D000069058:Vardenafil Dihydrochloride; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5