title: Investigation of the effects of the level of glycemic control on erectile function and pathophysiological mechanisms in diabetic rats.
abstract: BACKGROUND
  Poor glycemic control is associated with erectile dysfunction (ED); however, differences in ED according to the level of glycemic control have been poorly investigated.
  
  
  OBJECTIVE
  The aim of this paper is to investigate the change in erectile function according to the level of glycemic control and to clarify the pathophysiological mechanism of diabetes-associated ED.
  
  
  METHODS
  Streptozotocin was injected into 55 male Sprague-Dawley rats classified into four groups: control (group 1), diabetes with multiple insulin injections (group 2), diabetes with a single injection (group 3), and untreated diabetes (group 4). Daily insulin injections in groups 2 and 3 were administered for 4 weeks after 10 weeks of diabetic induction.
  
  
  METHODS
  The main outcome measures are the anova or Kruskal-Wallis tests to evaluate glycosylated hemoglobin (HbA1c), testosterone levels, the ratios of intracavernosal pressure to mean arterial pressure (ICP/MAP), area under the ICP curve to MAP (AUC/MAP), and changes in cavernous tissue and protein expression related to Rho kinase and nitric oxide pathways.
  
  
  RESULTS
  HbA1c levels were different between pairs of groups. Group 4 showed the lowest erectile parameters and group 2 showed near normal level. No differences in erectile parameters were found between groups 1 and 2 or between groups 3 and 4, except the ratio of AUC to MAP for group 1 was significantly higher than that of group 2 (20 Hz stimulation). Decrease in erectile function of group 2 was related to decreased expression of nitrergic nitric oxide synthase or decreased testosterone level compared with group 1. Groups 2 and 3 showed significant differences in erectile parameters, which were associated with difference in apoptotic index. Groups 3 and 4 showed no differences in erectile parameters, although these groups had significant differences in apoptotic index, smooth muscle component, and protein expression ratios of phosphorylated to total myosin phosphatase target subunit 1, endothelial nitric oxide synthase, and Akt.
  
  
  CONCLUSIONS
  Improvement in glycemic control assists recovery from diabetes-associated ED; however, only tight glycemic control can provide recovery from ED to a near normal status.
authors.affiliation: Department of Urology, Seoul National University Boramae Hospital, Seoul, Korea.
authors.forename: Sung Yong
authors.initials: SY
authors.lastname: Cho
authors.forename: Ji Sun
authors.initials: JS
authors.lastname: Chai
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Lee
authors.forename: Kwanjin
authors.initials: K
authors.lastname: Park
authors.forename: Jae-Seung
authors.initials: JS
authors.lastname: Paick
authors.forename: Soo Woong
authors.initials: SW
authors.lastname: Kim
mesh_terms: D000818:Animals; D048909:Diabetes Complications / Q000503:physiopathology / Q000517:prevention & control*; D003920:Diabetes Mellitus / Q000097:blood / Q000188:drug therapy*; D003921:Diabetes Mellitus, Experimental; D007172:Erectile Dysfunction / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D006442:Glycated Hemoglobin / Q000378:metabolism*; D007328:Insulin / Q000008:administration & dosage*; D008297:Male; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D010410:Penile Erection / Q000187:drug effects; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000097:blood
chemical_list: D006442:Glycated Hemoglobin; D007328:Insulin; D052250:Nitric Oxide Synthase Type III; D013739:Testosterone