title: [Growth hormone enhances regeneration of nNOS-containing nerve fibers in the aged rat penis].
abstract: OBJECTIVE
  To investigate the effects of growth hormone (GH) on the erectile function and the number of neuronal nitric oxide synthase (nNOS) -containing nerve fibers in the penis of aged rats.
  
  
  METHODS
  Twenty-four aged male SD rats (18 months) were randomized into 2 groups: GH intervention group and control group. After four and eight weeks, a half of each group were selected and tested for erectile function after apomorphine (APO) injection and then sacrificed for the detection of nNOS-containing nerve fibers in the penis by streptavidin-peroxidase conjugated method (SP method).
  
  
  RESULTS
  After four weeks, the erectile function and the number of nNOS-containing nerve fibers showed no significant difference between the GH intervention group and the control group (P > 0.05). After eight weeks, the erection frequency was significantly different (P < 0.05) between the two groups, while the erection rate was not. The number of nNOS-containing nerve fibers in the GH intervention group was significantly larger than that in the control group (P < 0.01).
  
  
  CONCLUSIONS
  GH enhances the regeneration of nNOS-containing nerve fibers in the penis and improves the erectile function of the aged rat.
authors.affiliation: Department of Urology, Zhongnan Hospital, Wuhan University, Wuhan, Hubei 430071, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Huang
authors.forename: Li-Quan
authors.initials: LQ
authors.lastname: Hu
authors.forename: Bin-Qun
authors.initials: BQ
authors.lastname: Tian
mesh_terms: D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D019382:Human Growth Hormone / Q000494:pharmacology*; D007150:Immunohistochemistry; D008297:Male; D009412:Nerve Fibers / Q000201:enzymology / Q000502:physiology*; D009416:Nerve Regeneration / Q000187:drug effects*; D052248:Nitric Oxide Synthase Type I / Q000032:analysis; D010410:Penile Erection / Q000187:drug effects*; D010413:Penis / Q000201:enzymology / Q000294:innervation*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D019382:Human Growth Hormone; D052248:Nitric Oxide Synthase Type I; D001058:Apomorphine