title: Effect of periodontitis on erectile function and its possible mechanism.
abstract: BACKGROUND
  Periodontitis is one of the important risk factors resulting in cardiovascular diseases. Erectile dysfunction (ED) is strongly correlated with cardiovascular diseases. The expression of endothelial nitric oxide synthase (eNOS) in penile tissue has an important role in the mechanism of erection.
  
  
  OBJECTIVE
  To investigate the effect of periodontitis on erectile function and the possible mechanism.
  
  
  METHODS
  After induction of periodontitis in rat, the ratio of maximum intracavernosal pressure/mean arterial pressure (ICPmax /MAP)×100, the expression of eNOS in penile tissue, the level of serum C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α), and the ultrastructural changes of the cavernous tissue were examined and compared between periodontitis rats (group A) and control rats (group B).
  
  
  METHODS
  Periodontitis significantly decrease not only the ICPmax/MAP×100 and the expression of eNOS but also the activity of NOS and the level of cyclic guanosine monophosphate (cGMP) in cavernous tissue of rat.
  
  
  RESULTS
  After electrostimulation by 3 and 5 voltage, the ratio of ICPmax /MAP×100 in group A was significantly less than that in group B (19.54±6.16 vs. 30.45±3.12; 30.91±5.61 vs. 50.52±9.52, respectively; P<0.05).The level of serum CRP and TNF-α in group A is significantly higher in group B (P<0.05).The quantitative real-time reverse transcription polymerase chain reaction study demonstrated no statistically significant difference in the expression of mRNA of eNOS in cavernous tissue between the two groups (P>0.05). But there was significant decrease in eNOS protein of the cavernous tissue in group A than in group B (P<0.05). Total NOS activity and cGMP level in cavernosal tissue were significantly lower in group A than in group B (P<0.05). There was no significant alternation occurred in the ultrastructures of penile cavernous tissue.
  
  
  CONCLUSIONS
  The function of penile erection is impaired by periodontitis. The decreased in the expression of eNOS and NOS activity in penile cavernous tissue caused by mild systemic inflammatory status in periodontitis may be one of the important risk factors of ED.
authors.affiliation: Department of Urology, Affiliated Hospital, Luzhou Medical College, Department of Statistics, Luzhou, China.
authors.forename: Zili
authors.initials: Z
authors.lastname: Zuo
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.forename: Rui
authors.initials: R
authors.lastname: Jiang
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Junxiang
authors.initials: J
authors.lastname: Liu
authors.forename: Haifan
authors.initials: H
authors.lastname: Yang
authors.forename: Yong
authors.initials: Y
authors.lastname: Cheng
mesh_terms: D000818:Animals; D001794:Blood Pressure; D015153:Blotting, Western; D002097:C-Reactive Protein / Q000032:analysis; D006152:Cyclic GMP / Q000032:analysis; D007172:Erectile Dysfunction / Q000209:etiology*; D008297:Male; D046529:Microscopy, Electron, Transmission; D019001:Nitric Oxide Synthase / Q000032:analysis; D052250:Nitric Oxide Synthase Type III / Q000032:analysis; D010413:Penis / Q000098:blood supply / Q000737:chemistry / Q000503:physiopathology; D010518:Periodontitis / Q000150:complications*; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D006152:Cyclic GMP