title: [Erectile function of male rats in different age groups: an experimental study].
abstract: OBJECTIVE
  To explore the relationship between aging and erectile function changes in rats in order to establish a rat model of aging-related erectile dysfunction (ED).
  
  
  METHODS
  Eighty male Wistar rats were equally divided into four age groups (3-, 6-, 12- and 18-month) and treated with intragastric administration of sildenafil citrate (Sn) for penile erection tests. Twenty 3-month-old female Wistar rats were randomized to four groups as oestrous rat models. We recorded the rate and frequency of penile erections of the male rats in different age groups.
  
  
  RESULTS
  The rates of penile erection were 85%, 75%, 40% and 30% and erectile frequencies were 2.27 +/- 0.80, 2.00 +/- 0.61, 1.40 +/- 0.51 and 1.29 +/- 0.49 in the 3-, 6-, 12- and 18-month rats, respectively, with statistically significant differences among different age groups (P < 0.01). And their erectile function exhibited a tendency to decrease with the increase of age. Besides, comparison of the 3-month with the 6-, 12- and 18-month groups showed significantly reduced erectile function in the 18-month rats (P < 0.05) but no remarkable difference between the 3-month and the 6- and 12-month groups (P > 0.05).
  
  
  CONCLUSIONS
  Aging is one of the main risk factors of rat erectile dysfunction, and 18-month-old male rats are qualified for the establishment of the rat model of aging-related erectile dysfunction.
authors.affiliation: Department of Toxicology, College of Public Health, Xinjiang Medical University, Urumqi, Xinjiang 830054, China.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: He
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.forename: Wen-Yu
authors.initials: WY
authors.lastname: Li
authors.forename: Guo-Hong
authors.initials: GH
authors.lastname: Song
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.forename: Fang
authors.initials: F
authors.lastname: Geng
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D007172:Erectile Dysfunction / Q000503:physiopathology*; D008297:Male; D023421:Models, Animal; D010410:Penile Erection / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar